By using rock grinding experiment machine to grinding different groups of rock, Using the electron microscope scanning technology to analysis of the wear profile amplification and Contour arithmetic mean deviation Ra, outline of the root mean square deviation Rq and average roughness parameter R the three surface roughness parameters to measure the new grinding surface roughness, using the PDC diamond compact for further PDC grinding experiments in different roughness of the generated sections. Before and after the grinding experiment calculate the lose weight of PDC diamond compact with electronic balance scales, through the analysis of experimental result data concluded that the degree of wear of PDC bit and the roughness grinding profile had a certain linear relationship in the grinding experiments, namely with the increase of roughness the trend of PDC bit wear was from reducing to increasing, and the wear volume reached its lowest point in a certain roughness parameter. using the scanning electron microscopy to analyze the section of PDC wear, and concluded that the wear mechanism of PDC is mainly abrasive wear ,accompanied by fatigue wear and adhesive wear, the wear process of PDC is the process of cleavage. The better way of diamond abrasion wear is: Diamond from exposing to micro broken to cleavage to fall off in the end. The worst way is diamond directly fall off.