In the construction of deep exploration and scientific drilling, the reasonable selection and using of drill bit is one of key factors to improve the deep-hole drilling efficiency in the hard, brittle, crushed rock. Based on the analysis on the special rocks in Jinchuan scientific drilling and study on the distribution, holding and exposure of diamond in the bit by scanning electron microscope, the appropriate matrix materials for bit and diamond process parameters are found to prolong the service life of the diamond bit and improve the drilling efficiency.