SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Restricted Net Assets (Details) - CNY (¥)	Dec. 31, 2025	Dec. 31, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Percentage of after tax profit, transferred annually by PRC subsidiaries to statutory surplus fund	10.00%
Maximum percentage criteria for appropriation of after-tax profit of PRC subsidiaries to statutory surplus fund (as a percent)	50.00%
Restricted net assets	¥ 433,872,669	¥ 433,868,390

Represents the maximum percentage criteria expressed as a percentage of registered capital for the transfer of after-tax profit by subsidiaries in China to a statutory surplus fund. If the reserve fund exceeds the specified threshold of the registered capital, further appropriation is not required.

No definition available.

Name:	niu_CriteriaForAppropriationToStatutorySurplusFundMaximumThresholdAsPercentageOfRegisteredCapital
Namespace Prefix:	niu_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant