diff --git a/src/BaseSelect.tsx b/src/BaseSelect.tsx
index db09169b8..3208301d1 100644
--- a/src/BaseSelect.tsx
+++ b/src/BaseSelect.tsx
@@ -27,7 +27,7 @@ import Selector from './Selector';
 import type { RefTriggerProps } from './SelectTrigger';
 import SelectTrigger from './SelectTrigger';
 import TransBtn from './TransBtn';
-import { getSeparatedContent } from './utils/valueUtil';
+import { getSeparatedContent, isValidCount } from './utils/valueUtil';
 import SelectContext from './SelectContext';
 import type { SelectContextProps } from './SelectContext';
 
@@ -399,7 +399,7 @@ const BaseSelect = React.forwardRef<BaseSelectRef, BaseSelectProps>((props, ref)
   const { maxCount, rawValues } = React.useContext<SelectContextProps>(SelectContext) || {};
 
   const onInternalSearch = (searchText: string, fromTyping: boolean, isCompositing: boolean) => {
-    if (rawValues?.size >= maxCount) {
+    if (isValidCount(maxCount) && rawValues?.size >= maxCount) {
       return;
     }
     let ret = true;
@@ -409,7 +409,7 @@ const BaseSelect = React.forwardRef<BaseSelectRef, BaseSelectProps>((props, ref)
     const separatedList = getSeparatedContent(
       searchText,
       tokenSeparators,
-      maxCount && maxCount - rawValues.size,
+      isValidCount(maxCount) ? maxCount - rawValues.size : undefined,
     );
 
     // Check if match the `tokenSeparators`
diff --git a/src/OptionList.tsx b/src/OptionList.tsx
index ee7e3cd80..9bb1a6c9c 100644
--- a/src/OptionList.tsx
+++ b/src/OptionList.tsx
@@ -14,6 +14,7 @@ import TransBtn from './TransBtn';
 import useBaseProps from './hooks/useBaseProps';
 import type { FlattenOptionData } from './interface';
 import { isPlatformMac } from './utils/platformUtil';
+import { isValidCount } from './utils/valueUtil';
 
 // export interface OptionListProps<OptionsType extends object[]> {
 export type OptionListProps = Record<string, never>;
@@ -72,7 +73,7 @@ const OptionList: React.ForwardRefRenderFunction<RefOptionListProps, {}> = (_, r
   const listRef = React.useRef<ListRef>(null);
 
   const overMaxCount = React.useMemo<boolean>(
-    () => multiple && typeof maxCount !== 'undefined' && rawValues?.size >= maxCount,
+    () => multiple && isValidCount(maxCount) && rawValues?.size >= maxCount,
     [multiple, maxCount, rawValues?.size],
   );
 
diff --git a/src/utils/valueUtil.ts b/src/utils/valueUtil.ts
index 920078f92..ffcad5af5 100644
--- a/src/utils/valueUtil.ts
+++ b/src/utils/valueUtil.ts
@@ -20,6 +20,10 @@ function getKey(data: BaseOptionType, index: number) {
   return `rc-index-key-${index}`;
 }
 
+export function isValidCount(value?: number) {
+  return typeof value !== 'undefined' && !Number.isNaN(value);
+}
+
 export function fillFieldNames(fieldNames: FieldNames | undefined, childrenAsData: boolean) {
   const { label, value, options, groupLabel } = fieldNames || {};
   const mergedLabel = label || (childrenAsData ? 'children' : 'label');