In order to further improve the drilling performance of polycrystalline diamond composite (PDC) bit in deep hard formation and restrain the occurrence of the viscous sliding phenomenon, a circular saw-shaped imitation tooth based on the bionic similarity principle and saw-shaped tooth structure was proposed based on the mole claw toe as the prototype. Based on elastic-plastic mechanics and finite element nonlinear dynamics theory, a simulation model of rock breaking of cutter and bit was established. The rock-breaking process of the serrated tooth and circular serrated tooth was compared, and the whole drilling process of the two kinds of serrated bit was compared. The results show that the circular arc sawing teeth are mainly used to break rock by plow and shovel, which can concentrate the load, reach the yield limit of rock more easily, and make the rock more easily broken by tensile stress. The cutting force is reduced by 15.8% compared with the sawing teeth, and the efficiency is higher. The bit with a circular saw bionic PDC teeth can break more rock, improve the footage significantly, and suffer less torque, which can effectively solve the viscous sliding of the bit. The research results have important reference values for the design of high-performance drill bits in China.