Abstract: Simulating the water chemistry of the PWR primary loop, the impact wear tests of stellite-6 which used in CRDM were carried out at different temperature and different impact force by using a specially designed impact wear test device. Results showed that the effect of temperature was not obvious when the sample was under normal impact force. The size loss of the sample was approximate 1×10-8 mm, and the weight loss of the sample was approximate 2×10^-6 mg, after 1 cycle impact. The primary wear mechanism of stellite-6 is plastic deformation and fatigue flack under high impact force. The size loss of the sample was approximate 1.3×10^-7mm, 4.7×10^-7 mm and 5.3×10^-7mm, and the weight loss of the sample was approximate 7.5×10^-6 mg, 4.17×10^-5mg and 4.83×10^-5mg at room temperature, 90℃ and 150℃ respectively.