In order to compare the rock breaking effect of conical PDC cutters and conventional PDC cutters, this paper analyzed the influences of wear height , rock sample, weight on bit(WOB)and others factors of rock breaking of conical PDC cutter and conventional PDC cutter, through single cutter rock breaking test. The results showed that, given the certain WOB, when drilling soft rocks(grey slate, green slate, marble), cutting depth of concial PDC cutter is less than the new conventional PDC cutters’, but is better than wear conventional PDC cutters’. With the increase of rock hardness, the cutting depth of concial PDC cutter approximates to new conventional PDC cutters’. When drilling hard rocks(limestone or basalt), if WOB is less than a certain value , the cutting depth of new conventional PDC cutter is better than the conical PDC cutters’, but if WOB is more than this certain value, cutting depth of concial PDC cutter is better than new conventional PDC cutters". The experimental results could provide reference for the design of hybrid bit.