Conical nuts not only reduce the consumption of raw materials by about 17%, but also have higher antitheft ability compared with ordinary hexagonal nuts. The use of cone nuts can improve the safety of the equipment. However, due to the lack of the corresponding disassembling tool, the cone nut has not been used in the engineering field. A special wrench for disassembling the cone nut was designed,and the working principle and structural design process were introduced.