The invention relates to an automobile electronic control unit (ECU) secret key simulation implementation method, a system and a verification method thereof. The automobile ECU secret key simulation implementation method includes that an automobile ECU simulation operating model is constructed and operated in a computer, an encryption unit is connected with the computer in a communication mode, the encryption unit has the same encryption processing business rules with an encryption control which is used for generating a secret key in the automobile ECU, an automobile diagnostic apparatus is connected with the computer and a vehicle-mounted bus in a communication mode, required safety algorithm numbers are set by the automobile diagnostic apparatus, a signal request seed numbers are transmitted to the simulation operating model by the automobile diagnostic apparatus, the safety algorithm numbers and the seed numbers back fed and output from the simulation operating model are transmitted to the encryption unit so that the encryption unit can generate the secret key relevant to the safety algorithm numbers and the seed numbers, and a communication with the encryption unit is performed for an analysis to obtain the secret key. The automobile ECU secret key simulation implementation method, the system and the verification method thereof have the advantages that the development design efficiency is high, the usage is reliable, the application is convenient and fast, the cost is saved, debugging workload and difficulties are remarkably reduced, and the like.