Abstract: Railway train coupler is an important part of railway freight car connection. The wear of the coupler is too fast and the breakage is the important reason that the coupler can not be connected. According to the different heat treatment state of the new ZG25MnCrNiMo steel for the coupler, based on the actual working conditions of rail rail rail hook-tail pin hole and hook-tail pin, hook-tail sphere and plate, the wear test method of rotating pin cylinder surface and bearing ring inner hole surface relative motion, and 40Mn2 of hook tail pin and ZG25MnCrNiMo pin specimen from plate according to standard hardness were used to simulate the wear experiment at lower speed. The results show that the wear of friction pairs with similar hardness is small. From this, the law and suggestion of the wear performance of the rear part of the hook are obtained.