Abstract: In order to solve the cabin cover descent problem caused by fracture of the nozzle in the hydraulic chamber of the operating cylinder in a certain equipment lifesaving system, research and analysis on the installation force state, the working principle of the product, non-destructive detection and judgment of the nozzle, and the failure analysis are conducted. Through the finite element simulation and the failure recurrence, it is determined that the fracture reason is the external force overload. Combined with the cause of failure and the severity of quality and safety caused by the fracture, the related measures to prevent the nozzle from breaking due to misoperation and other factors are worked out so as to ensure the stability and reliability of product performance.