Method for checking insulation fault of high-voltage system of vehicle

The invention relates to the technical field of high-voltage detection, in particular to a method for checking an insulation fault of a vehicle high-voltage system, which comprises the following steps of: checking whether a specific fault code exists or not by using a diagnostic instrument, confirming that a propulsion system is activated, and detecting an isolation voltage increment parameter by using the diagnostic instrument; checking whether the isolation voltage increment parameter is less than 15V or not; and checking whether the insulation voltage increment parameter is less than 15V, checking whether the insulation test resistance parameter is less than 600K omega, and checking the isolation voltage increment parameter. According to the method, judgment in the aspects of diagnosis of computer fault codes, data streams and the like is combined and presented in a diagnosis tree mode, the operation process of maintenance technicians in the maintenance process is standardized, safe operation can be effect