Abstract: In open-hole sidetracking of offshore deep and hard reservoirs with high confining pressure, it is difficult for conventional drilling process and polycrystalline diamond compact (PDC) drill bits with conventional tooth shapes to penetrate formation, and rock breaking efficiency is limited as well. A true three-dimensional dynamic simulation model for open-hole sidetracking impact-induced rock breaking was established, and the rock breaking effects of different tooth shapes under the same action were compared. The rock breaking mechanism of three kinds of PDC teeth, namely, flat teeth, axe teeth, and prism teeth under impact load was analyzed, as well as the shear stress distribution at different moments of rock cutting and the damage difference of different special-shaped PDC teeth during rock breaking. The effects of circumferential dynamic load and axial static load of special-shaped PDC teeth under the torsional impact on the rock damage below the cutting surface were compared, as well as the impact of different PDC tooth shapes on the penetration depth and tangential force, and the rock breaking mechanism of special-shaped PDC teeth during sidetracking was revealed. It is found that the rock breaking efficiency of special-shaped PDC teeth are different under different rock breaking modes, different confining pressures, and different cutting inclination angles. The research results can provide a theoretical basis for the optimal design of the personalized one-trip PDC drill bit for sidetracking and rock breaking in hard formations.