This paper discussed the simulation which is on the basis of the CFD software, including 3 different temperatures and 2 different heating rates; and analyzed the distribution of the temperature field during the hot pressing sintering for bit. The simulation shows that the sintering temperature, heating rate and holding time have effect on the temperature distribution. The temperature differences between graphite mould and bit matrix rises when the sintering temperature rises. Within certain limits, the temperature difference will reduce as heating rate increases. As a result, the holding time should be considered based on the mould thickness, bit specifications and mould formula.