diff --git a/common/changes/@visactor/vchart/fix-interactions-element-select-default-4563_2026-09-20.json b/common/changes/@visactor/vchart/fix-interactions-element-select-default-4563_2026-09-20.json
new file mode 100644
index 0000000000..635be6953c
--- /dev/null
+++ b/common/changes/@visactor/vchart/fix-interactions-element-select-default-4563_2026-09-20.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@visactor/vchart",
+      "comment": "fix: skip default single-select when spec.interactions already registers element-select, so isMultiple multi-select works",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@visactor/vchart"
+}
diff --git a/packages/vchart/__tests__/unit/interaction/element-select.test.ts b/packages/vchart/__tests__/unit/interaction/element-select.test.ts
new file mode 100644
index 0000000000..a088482d69
--- /dev/null
+++ b/packages/vchart/__tests__/unit/interaction/element-select.test.ts
@@ -0,0 +1,152 @@
+import { DataSet, DataView } from '@visactor/vdataset';
+import type { ISeriesOption } from '../../../src/series/interface';
+import { PieSeries, registerPieSeries } from '../../../src/series/pie/pie';
+import type { IPieSeriesSpec } from '../../../src/series/pie/interface';
+import { ElementSelect } from '../../../src/interaction/triggers/element-select';
+import { Interaction } from '../../../src/interaction/interaction';
+import { TRIGGER_TYPE_ENUM } from '../../../src/interaction/triggers/enum';
+import type { IMark } from '../../../src/mark/interface';
+import type { IMarkGraphic } from '../../../src/mark/interface/common';
+import { initChartDataSet, seriesOption } from '../../util/context';
+
+registerPieSeries();
+
+const dataSet = new DataSet();
+initChartDataSet(dataSet);
+
+class TestPieSeries extends PieSeries<IPieSeriesSpec> {
+  protected _computeLayoutRadius() {
+    return 100;
+  }
+}
+
+const dummyEvent = {
+  on: (): void => undefined,
+  off: (): void => undefined,
+  emit: (): void => undefined
+};
+
+function createPieSeries(spec: Partial<IPieSeriesSpec> = {}) {
+  const dataView = new DataView(dataSet);
+  dataView.parse(
+    [
+      { type: 'oxygen', value: 46.6 },
+      { type: 'silicon', value: 27.72 },
+      { type: 'aluminum', value: 8.13 }
+    ],
+    {
+      type: 'array'
+    }
+  );
+
+  const series = new TestPieSeries(
+    {
+      type: 'pie',
+      data: dataView,
+      valueField: 'value',
+      categoryField: 'type',
+      ...spec
+    },
+    seriesOption({ dataSet }) as ISeriesOption
+  );
+  series.created();
+  series.init({});
+  return series;
+}
+
+function getSelectTriggers(series: PieSeries<IPieSeriesSpec>) {
+  return series.getInteractionTriggers().filter(item => item.trigger.type === TRIGGER_TYPE_ENUM.ELEMENT_SELECT);
+}
+
+function createGraphic(mark: IMark): IMarkGraphic {
+  const graphic = {
+    context: { markId: mark.id },
+    currentStates: [] as string[],
+    hasState(state: string) {
+      return graphic.currentStates.includes(state);
+    },
+    setStates(states?: string[] | null) {
+      graphic.currentStates = states ?? [];
+    }
+  };
+  return graphic as unknown as IMarkGraphic;
+}
+
+function getIsMultiple(trigger: ReturnType<PieSeries<IPieSeriesSpec>['getInteractionTriggers']>[number]['trigger']) {
+  return (trigger as { isMultiple?: boolean }).isMultiple;
+}
+
+function startSelects(selectTriggers: ReturnType<typeof getSelectTriggers>, graphics: IMarkGraphic[]) {
+  const instances = selectTriggers.map(({ trigger, marks }) => {
+    const interaction = new Interaction();
+    const instance = new ElementSelect({
+      ...(trigger as any),
+      marks,
+      event: dummyEvent,
+      interaction
+    });
+    return { interaction, instance };
+  });
+
+  graphics.forEach(graphic => {
+    instances.forEach(({ instance }) => instance.start(graphic));
+  });
+
+  return instances.map(({ interaction, instance }) => interaction.getStatedGraphics(instance) ?? []);
+}
+
+describe('element-select vs default select', () => {
+  test('interactions isMultiple accumulates without default single-select fighting it', () => {
+    const series = createPieSeries({
+      interactions: [
+        {
+          type: 'element-select',
+          isMultiple: true
+        }
+      ]
+    });
+
+    const triggers = series.getInteractionTriggers();
+    const selectTriggers = getSelectTriggers(series);
+
+    expect(selectTriggers).toHaveLength(1);
+    expect(getIsMultiple(selectTriggers[0].trigger)).toBe(true);
+    expect(triggers.some(item => item.trigger.type === TRIGGER_TYPE_ENUM.DIMENSION_HOVER)).toBe(true);
+    expect(triggers.some(item => item.trigger.type === TRIGGER_TYPE_ENUM.ELEMENT_HIGHLIGHT)).toBe(true);
+
+    const mark = selectTriggers[0].marks[0];
+    const statedLists = startSelects(selectTriggers, [createGraphic(mark), createGraphic(mark)]);
+
+    expect(statedLists.some(graphics => graphics.length > 1)).toBe(true);
+  });
+
+  test('default select without interactions stays single-select', () => {
+    const series = createPieSeries();
+    const selectTriggers = getSelectTriggers(series);
+
+    expect(selectTriggers).toHaveLength(1);
+    expect(getIsMultiple(selectTriggers[0].trigger)).toBe(false);
+
+    const mark = selectTriggers[0].marks[0];
+    const statedLists = startSelects(selectTriggers, [createGraphic(mark), createGraphic(mark)]);
+
+    expect(statedLists[0]).toHaveLength(1);
+  });
+
+  test('select.mode multiple still accumulates without interactions', () => {
+    const series = createPieSeries({
+      select: {
+        mode: 'multiple'
+      }
+    });
+    const selectTriggers = getSelectTriggers(series);
+
+    expect(selectTriggers).toHaveLength(1);
+    expect(getIsMultiple(selectTriggers[0].trigger)).toBe(true);
+
+    const mark = selectTriggers[0].marks[0];
+    const statedLists = startSelects(selectTriggers, [createGraphic(mark), createGraphic(mark)]);
+
+    expect(statedLists[0].length).toBeGreaterThan(1);
+  });
+});
diff --git a/packages/vchart/src/series/base/base-series.ts b/packages/vchart/src/series/base/base-series.ts
index 0e0b816711..35c3b19025 100644
--- a/packages/vchart/src/series/base/base-series.ts
+++ b/packages/vchart/src/series/base/base-series.ts
@@ -956,6 +956,14 @@ export abstract class BaseSeries<T extends ISeriesSpec> extends BaseModel<T> imp
     const { interactions } = this._spec;
     const res = this._parseDefaultInteractionConfig(mainMarks);
 
+    // Custom element-select is not isEqual to default select, so both would stay live and fight.
+    if (interactions?.some(interaction => interaction.type === TRIGGER_TYPE_ENUM.ELEMENT_SELECT)) {
+      const defaultSelectIndex = res.findIndex(item => item.trigger.type === TRIGGER_TYPE_ENUM.ELEMENT_SELECT);
+      if (defaultSelectIndex >= 0) {
+        res.splice(defaultSelectIndex, 1);
+      }
+    }
+
     if (interactions && interactions.length) {
       interactions.forEach(interaction => {
         const marks: IMark[] = filterMarksOfInteraction(interaction, this.getMarks());