diff --git a/src/InputNumber.tsx b/src/InputNumber.tsx
index 541be08f..1c8a0341 100644
--- a/src/InputNumber.tsx
+++ b/src/InputNumber.tsx
@@ -4,8 +4,7 @@ import KeyCode from 'rc-util/lib/KeyCode';
 import { composeRef } from 'rc-util/lib/ref';
 import getMiniDecimal, {
   DecimalClass,
-  roundDownUnsignedDecimal,
-  roundUpUnsignedDecimal,
+  roundUnsignedDecimal,
   toFixed,
   ValueType
 } from './utils/MiniDecimal';
@@ -46,11 +45,11 @@ const getDecimalIfValidate = (value: ValueType, precision: number | undefined, i
 
   const {negative, integerStr, decimalStr, negativeStr} = trimNumber(decimal.toString());
   const unSignedNumberStr = integerStr +'.' +  decimalStr;
-
+  
   if ((isMax && !negative) || (!isMax && negative)) {
-    return getMiniDecimal(negativeStr +  roundDownUnsignedDecimal(unSignedNumberStr, precision));
+    return getMiniDecimal(negativeStr +  roundUnsignedDecimal(unSignedNumberStr, precision, false));
   } else {
-    return getMiniDecimal(negativeStr +  roundUpUnsignedDecimal(unSignedNumberStr, precision));
+    return getMiniDecimal(negativeStr +  roundUnsignedDecimal(unSignedNumberStr, precision, true));
   }
 };
 
diff --git a/src/utils/MiniDecimal.ts b/src/utils/MiniDecimal.ts
index 6088b861..9fd57579 100644
--- a/src/utils/MiniDecimal.ts
+++ b/src/utils/MiniDecimal.ts
@@ -266,27 +266,20 @@ export default function getMiniDecimal(value: ValueType): DecimalClass {
 
 /**
  * round up an unsigned number str, like: 1.4 -> 2, 1.5 -> 2
+ * Or round down an unsigned number str, like: 1.4 -> 1, 1.5 -> 1
  */
-export function roundUpUnsignedDecimal(numStr: string, precision: number) {
+export function roundUnsignedDecimal(numStr: string, precision: number, roundUp: boolean) {
   const {integerStr, decimalStr} = trimNumber(numStr);
-  const advancedDecimal = getMiniDecimal(integerStr + '.' + decimalStr).add(
-    `0.${'0'.repeat(precision)}${5}`,
-  );
-  return toFixed(advancedDecimal.toString(), '.', precision);
-}
 
-/**
- * round up an unsigned number str, like: 1.4 -> 1, 1.5 -> 1
- */
-export function roundDownUnsignedDecimal(numStr: string,  precision: number) {
-  const {negativeStr, integerStr, decimalStr} = trimNumber(numStr);
-  const numberWithoutDecimal = `${negativeStr}${integerStr}`;
-  if (precision === 0) {
-    return integerStr;
-  }
-  return `${numberWithoutDecimal}.${decimalStr
-    .padEnd(precision, '0')
-    .slice(0, precision)}`;
+  // round up decimal part
+  const times = Math.pow(10, precision);
+
+  const roundFn = roundUp ? Math.ceil : Math.floor;
+  const decimalPart = roundFn(parseFloat(`0.${decimalStr}`) * times) / times;
+  // add decimal part and integer part 
+  const advancedDecimal = getMiniDecimal(integerStr).add(decimalPart);
+  
+  return toFixed(advancedDecimal.toString(), '.', precision);
 }
 
 /**
diff --git a/tests/input.test.tsx b/tests/input.test.tsx
index be4b98b2..a28cb359 100644
--- a/tests/input.test.tsx
+++ b/tests/input.test.tsx
@@ -59,6 +59,11 @@ describe('InputNumber.Input', () => {
     expect(wrapper.getInputValue()).toEqual('-98');
   });
 
+  it('input zero and precision is 0', () => {
+    const wrapper = prepareWrapper('0', {min: 0, precision: 0});
+    expect(wrapper.getInputValue()).toEqual('0');
+  });
+
   it('negative min with higher precision', () => {
     const wrapper = prepareWrapper('-4', {min: -3.5, precision: 0});
     expect(wrapper.getInputValue()).toEqual('-3');
diff --git a/tests/util.test.tsx b/tests/util.test.tsx
index a6702608..ffe7191e 100644
--- a/tests/util.test.tsx
+++ b/tests/util.test.tsx
@@ -2,8 +2,7 @@ import getMiniDecimal, {
   BigIntDecimal,
   DecimalClass,
   NumberDecimal,
-  roundDownUnsignedDecimal,
-  roundUpUnsignedDecimal,
+  roundUnsignedDecimal,
   toFixed,
   ValueType,
 } from '../src/utils/MiniDecimal';
@@ -154,19 +153,21 @@ describe('InputNumber.Util', () => {
     });
 
     it('round down', () => {
-      expect(roundDownUnsignedDecimal('77.89',  1)).toEqual('77.8');
-      expect(roundDownUnsignedDecimal('77.1',  2)).toEqual('77.10');
-      expect(roundDownUnsignedDecimal('77.81', 1)).toEqual('77.8');
-      expect(roundDownUnsignedDecimal('77.50', 1)).toEqual('77.5');
-      expect(roundDownUnsignedDecimal('77.5999', 0)).toEqual('77');
-      expect(roundDownUnsignedDecimal('77.0001', 0)).toEqual('77');
+      expect(roundUnsignedDecimal('0',  0, false)).toEqual('0');
+      expect(roundUnsignedDecimal('77.89',  1, false)).toEqual('77.8');
+      expect(roundUnsignedDecimal('77.1',  2, false)).toEqual('77.10');
+      expect(roundUnsignedDecimal('77.81', 1, false)).toEqual('77.8');
+      expect(roundUnsignedDecimal('77.50', 1, false)).toEqual('77.5');
+      expect(roundUnsignedDecimal('77.5999', 0, false)).toEqual('77');
+      expect(roundUnsignedDecimal('77.0001', 0, false)).toEqual('77');
     })
     it('round up', () => {
-      expect(roundUpUnsignedDecimal('77.89', 1)).toEqual('77.9');
-      expect(roundUpUnsignedDecimal('77.81', 1)).toEqual('77.9');
-      expect(roundUpUnsignedDecimal('77.89', 0)).toEqual('78');
-      expect(roundUpUnsignedDecimal('77.599', 0)).toEqual('78');
-      expect(roundUpUnsignedDecimal('77.01', 0)).toEqual('78');
+      expect(roundUnsignedDecimal('0',  0, true)).toEqual('0');
+      expect(roundUnsignedDecimal('77.89', 1, true)).toEqual('77.9');
+      expect(roundUnsignedDecimal('77.81', 1,true)).toEqual('77.9');
+      expect(roundUnsignedDecimal('77.89', 0,true)).toEqual('78');
+      expect(roundUnsignedDecimal('77.599', 0,true)).toEqual('78');
+      expect(roundUnsignedDecimal('77.01', 0,true)).toEqual('78');
     })
   });
 });