Abstract: In order to improve the performance of diamond bit, impregnated diamond bit was prepared by adding different mass of hard brittle abrasive into matrix and drilling performance was tested by drilling experiments. The effect of hard brittle abrasive on drilling performance was studied. The results show that adding 5.5% SiC particle had better effect and the drilling efficiency increased by 55.14% compare with common bit. The hard brittle abrasive in the matrix can improving the microstructure of bit. The hard brittle abrasive left in the down hole can improve the erosion performance of washing fluid to matrix and increase the truing and sharpening effect on the single diamond.