Vanadium-Chromium composite layer is formed on the surface of cast steel by the method of V-EPC cast penetration. The dry sliding friction wear properties of composite layer are studied on MM200 friction wear testing machine in this paper. The wear surface feature of samples is also observed by SEM and the wear mechanism of samples is analyzed. The result has shown that comparing with the matrix, the wear resistance of composite layer is advanced evidently. The wear rate of composite layer is only eighth to matrix. With the increase of load and the decrease of Vanadium iron in penetrating regent, the wear rate of composite layer increase. The mechanism of composite layer is mainly oxidation and fatigue flake produced by the initiation and expansion of crack.