Abstract: For the sake of further studying the influence of cutting depth to cutting performance，in this article conical pick and coal models are established through discrete element software PFC3D. The simulation of pick linear cutting coal is finished at different cutting depth; recording the forces simultaneously. The accuracy of the simulation results is proved by comparing the results of the numerical simulation with those of the theoretical calculation by means of regression analysis. Then the spectral analysis of the results is performed. The results show that the average cutting force of the conical pick cutting coal and the cutting depth have obviously linear dependence; the larger the cutting depth, the higher the force is. The load fluctuation and the percentage of coal powder are first decrease then increase with the increasing of the cutting depth, while the cutting performance is better at the cutting depth from 15 mm to 20 mm.