Abstract: For the special demand of highly rotational speed and resistant to wear of automobile gearbox transform system, the 300h high speed wear bench test for inner-outer compound meshing Hy-Vo silent chain was conducted. The automobile gearbox Hy-Vo silent chain wear characteristics were researched. The local wear micrograph of the contact area of chain hinge and link plate outline with the sprocket tooth was analyzed. The results indicate that the integrated wear of automobile gearbox Hy-Vo silent chain consisted of the wear of non-circular pin and link plate. The wear mechanism of non-circular pin was fatigue wear with slight contact pitting.