In lathe operation, the most frequently used wrenches are chuck wrenches and tool holder wrenches, which are different in structure and function and cannot be replaced, and forgetting to remove the wrenches will cause safety accidents. To solve the above problems, this paper designs a new type of wrench, which integrates the functions of chuck wrench, tool holder wrench and various screwdrivers, and can easily change the form of wrench by certain operation, which improves the production efficiency and eliminates the safety hazards.