The vibration of highspeed shaft bearing in wind turbine gearbox is an important factor causing potential safety hazard of wind turbine,and the coupling effect of the shaft system will have an important influence on the bearing vibration. Taking a 750 kW multisupport shaft system of highspeed shaft of wind turbine gearbox as the research object, based on the central difference method, a modeling method for analyzing the coupling vibration of multisupport shaft system was proposed, and the simulation calculation was carried out by using MATLAB. The results show that the vibration amplitude of the coupling model is smaller than that of the uncoupled model; the contact force of different bearings is different, and the closer the load point is to the bearing, the greater the contact force is; when the load point is close to the single bearing, the contact force is much greater than of the double bearing on the other side.