Car off-line testing method and system

The embodiment of the invention provides a car off-line testing method and system. According to the car off-line testing method and system, test items of electrical systems on a CAN bus are arranged to be in a sequential execution series connection mode, test items of electrical systems on different CAN buses are arranged to be in a sequential execution parallel connection mode, and therefore detection of a plurality of electrical systems and initialization of the items can be completed in a station in a concentrated mode, the total testing time is shortened, and production efficiency is improved. Besides, when the items to be tested need to be increased or reduced, only the test items of the CAN buses corresponding to the items to be tested need to be adjusted, and therefore workload and difficulty of adjustment work are reduced.