Abstract: The hydraulic impactor based drilling technology is one effective method to improve the rate of penetration (ROP) and drilling efficiency of hard formations in deep wells. In order to study the actual working performance of jet-suction impactors, this paper carried out finite element simulation analysis on the existing jet-suction impactors, studied the influences of hammer mass, pump displacement and nozzle diameter on impact energy and impact frequency, and selected the optimal working parameters. It is indicated that at the constant boundary condition, pump displacement and nozzle diameter, the impact energy of the tool increases and the impact frequency decreases with the increase of the hammer mass. When the hammer mass is 9.675 kg, both impact energy and impact frequency (1 397 times/min) are higher and the hammer mass consumed in the backward stroke is less. And at this moment, the hammer mass is optimal. When the nozzle diameter is constant, both internal pressure drop and impact frequency of the tool increase with the increase of the pump displacement. When the pump displacement is constant, both internal pressure drop and impact frequency of the tool decrease with the increase of the nozzle diameter. By virtue of the finite element method, the working performance of impactors under different working parameters was simulated and analyzed, so as to lay the good base for its actual application in the field.