n light of the dynamic characteristics of the cutting head and cantilever system of the roadheader under different pick loads (sharp picks and blunt picks), the bending-torsional coupling nonlinear dynamic model of the cutting head-rotor-bearing system of the roadheader is established. Considering the spline meshing clearance between the cutting head and the rotating shaft, and the nonlinear factor of the rolling bearing contact, the dynamic differential equations of the cutting head rotor system of the roadheader are derived. Then, the dynamic response characteristics of the cutting head rotor system under time-varying load are analyzed. The results show that under the condition of sharp picking, the cutting head rotor system is in chaotic and quasi-periodic motion state at low speed between 15 and 20, and the system is in periodic motion after the speed is increased. While the picks are blunt, the vibration of the cutting head rotor system is obviously aggravated, the chaotic motion range is increased, and the frequency amplitude fluctuates significantly. The system changes from chaotic motion to periodic motion with the increase of cutting speed at the given premise of cutting coal seam hardness and cutting thickness. The dynamic analysis results provide a theoretical basis for the vibration reduction and dynamic design of the roadheader.