The forced vibration of the tilting rubber tree cutting device caused by external excitation during operation will lead to the reduction of the quality of the cutting operation and the structural damage of the mechanical system. To solve this problem, this paper simulated the forced vibration of the cutting device under the action of external excitation by applying cutting resistance and changing rotation speed, and carried out the motion calculation of the transmission structure to prove the relationship between cutting resistance, rotation speed and forced vibration of the cutting device. Combined with ANSYS Workbench and ADAMS, the forced vibration is compared and analyzed to explore the motion characteristics of the cutting device. According to the results of the simulation test, the feasibility of reducing the impact of the impact load on the transmission structure is explored by adding damping as a vibration isolation method. The test shows that the operating frequency of the transmission structure is only 2.7% of the natural frequency of the first mode, so the structure will not be damaged due to self‑excited vibration. Under the action of external excitation, the vibration of the center of mass of the eccentric shaft is mainly radial vibration, and the impact load presents nonlinear response with the increase of cutting resistance and rotation speed. By adopting the method of vibration isolation, the vibration acceleration amplitude of the transmission structure decreases by 30.01% and 32.64% in the simulation test and 31.14% and 28.38% in the real test respectively under the two conditions of no load and load. The difference between the two test methods is small, the reduction is obvious and the movement performance of the transmission structure tends to be stable.