Abstract: The problem of insufficient locking force of screw sleeve is studied by using TRIZ. Through the function analysis, cause and effect analysis, conflict area analysis and other methods of TRIZ, the contradictory points in the screw sleeve connection technology system are located. By tackling the assembly clearance and locking force in the process of screw sleeve locking, four root causes to the problem of insufficient locking force are located and solutions are formulated by means of conflict matrix, material field model, effect knowledge base and patent search tool of TRIZ. The solution is verified by field test, and the optimal solution is finally obtained and applied in production practice.