Taking a certain high-speed locomotive traction gear material of 42CrMo 17CrNiMo6 as the object, the influence of contact load and relative sliding velocity on its friction and wear properties was studied in the pin-on-disk reciprocating friction and wear tester. The worn surface morphologies were observed on a scanning electron microscope and the friction and wear mechanism of the locomotive gear materials was analyzed. Results show that the friction coefficient of locomotive traction gear materials is decreased and then becomes stable gradually with the increasing of normal contact load and relative velocity. The ploughs are generated on the worn surfaces of the locomotive traction gear materials. Due to the increase of the load and velocity, the space of ploughs is widened and the worn surface is smoothed, which causes the decreasing of the friction coefficient for the locomotive traction gear material.