Aiming to the drilling characteristics of hard rock in deep borehole, a new kind of impregnated diamond bit was redesigned from structure, matrix formula, parameters of diamond and etc. in the paper. According to the design, the new long life impregnated diamond bit was developed, which could significantly improve drilling efficiency and reduce drilling construction cost in deep borehole. Compared with the conventional bit, the lifetime of the new diamond bit increased by over 1.5 times, and its drilling rate was improved by over 20%. With the new bit, the drilling efficiency in deep borehole hard rock could be improved immensely.