Abstract: To explore the variety and influence factors of cutting force in the process of conical pick cutting coal,a Ro- tary Cutting Model (RCM) of conical pick was proposed based on the Evans’s linear cutting model. The expressions of the cutting angle and cutting thickness in the process of conical pick cutting coal were deduced on the basis of cut- ting trajectory of shearer conical pick. Then the possible maximum change of cutting angle was calculated with the cut- ting parameters range in cutting process,which would reach ±4°. According to the RCM,the relationship between the cutting force and cutting angle,semi-tip angle was obtained under a certain cutting thickness condition. The relation- ship shows that the cutting force maintains a smooth change before and after the maximum cutting thickness when the semi-tip angle is 36°. Put the cutting angle and cutting thickness in cutting process into the RCM,it showed that the traction speed has the greatest influence on cutting force,and the angular velocity and cutting radius of drum have a less influence. The derived formulas and conclusions can provide a theoretical basis and guidance for the future design of shearer and conical pick.