In this paper,the effect of heat treatment on microstructure of high chromium cast iron was analyzed by metallographic microscope and scanning electron microscope.The effect of heat treatment on mechanical properties of high chromium cast iron was studied by hardness test and wear resistance test. The results show that when the solution temperature is below 920 ℃,the microstructure after quenching and tempering is as as-cast. When the solution treatment temperature is 920 ℃ or above,the as-cast microstructure disappears after quenching+tempering,and the quenching microstructure appears.As the solution temperature increases,the hardness and wear resistance of high chromium cast iron first increases and then decreases. At 870 ℃,the hardness reaches the maximum value and the wear resistance is the best. Cryogenic treatment can not improve the wear resistance of high chromium cast iron in ascast microstructure,but can improve the wear resistance of quenched high chromium cast iron.