Abstract: The new-typed W6Mo5Cr4V8 In high vanadium high speed steel used for numerical control machine were heat treated at various temperatures to test and analyze the microstructure,impact property and wear resistance. The results show that with heat treatment temperature increasing from 1 050 ℃ to 1 150 ℃ the grain size of the steel first decreases then increases,and both the impact property and wear resistance of the steel first enhance then decline.M₂C carbide is decomposed when the heat treatment temperature is between 1 080 ℃ and 1 150 ℃. The optimized heat treatment temperature is 1 080 ℃. Compared with those of the steel heat treated at 1 150 ℃,the impact absorption energy and wear volume of the steel with heat treatment at 1 080 ℃ increases by 46% and decreases by 48%,respectively.