The impact wear tests of Zr-4 alloy tubes against Inconel718 Nickel alloy plates were carried out on a small load impact wear test machine JDTRI50 under the impact frequency of 10 Hz,the impact loads from 10 N to 40 N respectively,the impact times from 50 000 to 100 000.The impact wear behavior and mechanism of damage of the nuclear fuel rod cladding Zr-4 alloy tube were studied.The results show that,with the increasing of impact load,the wear scar width is increased and impact damage is aggravated at fixed impact times;with the increasing of impact times,the impact damage area and depth of Zr-4 alloy cladding tube is increased at fixed load.The oxygen content of wear debris shows a process of change of a rapid increase,a slowdown and a basic stability in oxygen content.The mechanism of impact wear mainly includes the successive emergence,mutual conversion and synergistic effect of plastic deformation,oxidation wear and fatigue spalling.