diff --git a/src/util/number.ts b/src/util/number.ts
index 662695f7f7..35dd4ef67a 100644
--- a/src/util/number.ts
+++ b/src/util/number.ts
@@ -229,8 +229,12 @@ export function round(x: number | string, precision: number, returnStr?: boolean
         // precision utils (such as getAcceptableTickPrecision) may return NaN.
         return returnStr ? '' + x : +x;
     }
-    // Avoid range error
-    precision = mathMin(mathMax(0, precision), TO_FIXED_SUPPORTED_PRECISION_MAX);
+    // Avoid range error. Do not clamp large precision to 20 because it may
+    // over-round tiny values such as 3e-21 to zero.
+    if (precision > TO_FIXED_SUPPORTED_PRECISION_MAX) {
+        return returnStr ? '' + x : +x;
+    }
+    precision = mathMax(0, precision);
     // PENDING: 1.005.toFixed(2) is '1.00' rather than '1.01'
     x = (+x).toFixed(precision);
     return (returnStr ? x : +x);
diff --git a/test/ut/spec/scale/interval.test.ts b/test/ut/spec/scale/interval.test.ts
index 545d967ff7..20f0c84c73 100755
--- a/test/ut/spec/scale/interval.test.ts
+++ b/test/ut/spec/scale/interval.test.ts
@@ -68,6 +68,29 @@ describe('scale_interval', function () {
             expect(ticks[ticks.length - 1].value).toEqual(max);
         });
 
+        it('ticks_tiny_max', function () {
+            chart.setOption({
+                xAxis: {},
+                yAxis: {
+                    type: 'value',
+                    scale: true,
+                    max: 2.324097633474072e-20
+                },
+                series: [{
+                    type: 'line',
+                    data: [1e-20]
+                }]
+            });
+
+            const yAxis = getECModel(chart).getComponent('yAxis', 0) as CartesianAxisModel;
+            const ticks = yAxis.axis.scale.getTicks();
+
+            expect(ticks.length).toBeGreaterThan(2);
+            ticks.forEach(function (tick) {
+                expect(tick.value).toBeFinite();
+            });
+        });
+
         it('ticks_small_value', function () {
             chart.setOption({
                 tooltip: {},
diff --git a/test/ut/spec/util/number.test.ts b/test/ut/spec/util/number.test.ts
index 2c26932148..b51949f50e 100755
--- a/test/ut/spec/util/number.test.ts
+++ b/test/ut/spec/util/number.test.ts
@@ -958,6 +958,12 @@ describe('util/number', function () {
             expect(nice(3900000000000000000021)).toEqual(5000000000000000000000);
             expect(nice(0.00000000000000000656939, true)).toEqual(0.000000000000000005);
             expect(nice(0.00000000000000000656939)).toEqual(0.00000000000000001);
+            const niceTiny3 = nice(2.648195266948144e-21, true);
+            const niceTiny5 = nice(4.648195266948144e-21, true);
+            expect(niceTiny3).toBeGreaterThan(0);
+            expect(niceTiny3).toBeLessThan(1e-20);
+            expect(niceTiny5).toBeGreaterThan(0);
+            expect(niceTiny5).toBeLessThan(1e-20);
             expect(nice(0.10000000000000000656939, true)).toEqual(0.1);
             expect(nice(0.10000000000000000656939)).toEqual(0.2);
         });