This paper introduces two kinds of diamond surface pretreatment technologies, namely titanium coating and pit treatment, which are commonly used in diamond tool manufacturing. The efficiency and life of 2 bits made of pretreated and conventional diamonds when drilling reinforced concrete are compared and analyzed. Drilling experiments show that compared with that of conventional bit, the life of the bit made of Ti-coated diamond can be increased by more than 30%, and that the service life and drilling efficiency of bits made of pit-treated diamonds are increased by 35% and 10% respectively with lower concentration of added diamond. Therefore, pit treatment is a rapidly developing technology at present.