The invention discloses a detecting method and system for validity of new-energy vehicle data. The method comprises the following steps: acquiring data of the new-energy vehicle; filtering invalid data and abnormal data of the new-energy vehicle based on the vehicle data, thereby obtaining the valid and normal data; calculating the invalid mileage of the new-energy vehicle based on the obtained data, wherein the invalid mileage includes transition mileage and mileage to be deducted for current detection; calculating the valid mileage based on the online mileage and the invalid mileage; determining whether the valid mileage is within the valid mileage threshold; if so, determining whether the vehicle data are the data produced by the new-energy vehicle in running; and if not, determining whether the vehicle data are not the data produced by the new-energy vehicle in running. With the adoption of the detecting method and system, the detection accuracy of the validity of the new-energy vehicle data can be improved; the probability of expense subsidizing deception of the new-energy vehicle can be minimized; and the method and the system are applicable to high-speed operation of mass data.