Abstract: Through an HMB type hydraulic spring mechanism, the GIS combination electrical appliance produced by ABB is analyzed in depth due to abnormal alarm of the oil pump, the hydraulic mechanism cannot build pressure normally, and the failure of energy storage fails. The basic structure, operation principle and accident scene of the GIS using HMB hydraulic spring mechanism are comprehensively introduced, and a set of non-stop power treatment measures and verification experimental devices for energy storage failure of HMB hydraulic spring mechanism are designed, which provides relevant basis for similar typical fault research and judgment in the future.