Method and system for safely accessing ECU (Electronic Control Unit) equipment of whole vehicle

The invention provides a vehicle ECU equipment safety access method and system, and the method comprises the steps: generating a DID parameter based on a written random number during offline calibration; receiving a first key value sent by the diagnosis equipment; according to a locally stored DID parameter and a seed, obtaining a second key value through calculation by using a preset calculation formula; and comparing the first key value with the second key value, and determining the access authority of the diagnosis equipment to the ECU equipment according to a comparison result. According to the method, the DID parameters, the seed and the preset calculation formulas generated by different ECU devices in the whole vehicle are different, finally calculated key values are different, namely, the safety algorithms of the different ECU devices in the whole vehicle are different, and even if the safety algorithm of one ECU device is leaked, safety algorithms of all ECU equipment in the whole vehicle cannot be le