In terms of the problem of cutting head position control of boom-type roadheader,the nonlinear model of the cutting part system of roadheader was established.The cutting part had a proportional valve controlled double cylinder hydraulic system of rotary part and a proportional valve controlled double cylinder synchronous hydraulic system of lifting part,and the pressure and flow characteristics of the hydraulic system of the rotary part and lifting part were analyzed.Combined with the kinematics and dynamics analysis of the mechanical system of the rotary part and lifting part,the nonlinear mathematical model of the cutting part system was established.The simulation model of the cutting part system was constructed in MATLAB/Simulink environment.Based on the model,the typical cutting conditions of roadheader were simulated.The simulation results show that the rotation angle and lifting angle of the cutting part can track the target angle well,and the model can reflect the changes of various parameters in the cutting part system.It provides a theoretical basis for the precise positioning of the cutting head of the roadheader and the automatic cutting of the roadheader.