Dongfanghong-LX754 tractor and Huaifeng1LS-740 subsoiler were used to study the effects of different positions of farm tools on the vibration characteristics of tractor with suspended farm tools. CATIA software was used to establish simplified geometric model of tractor and farm tools. MATLAB was used to write random road surface file,which was imported into ADAMS to write tire property file and establish the mechanical system model of farm tool,tractor and road surface. Effects of the parameters of the suspension device on the vertical vibration acceleration of the driver,the pitch vibration angular acceleration at the seat installation and the vertical vibration acceleration of the tractor body were obtained by simulation. The results showed that when the angle between the inner lifting arm and the horizontal direction increased from 20° to 70°,the driver acceleration peak value reduced to 17.61 from 30.09 m/s2. The peak frequency of vertical vibration increased from 1.36 to 2.12 Hz. Seat installed in longitudinal vibration angular acceleration peak value reduced to 7.56 from 11.12 rad/s2. Tractor barycenter vertical vibration acceleration peak value reduced to 29.33 from 42.42 m/s2. It will provide an important reference for designing vibration damping system of tractor.