The water-cooled gearbox is the key component of bell-less blast furnace top.Its function is to drive and control the rotation and tilt of the material distribution chute to meet the requirements of different material distribution.BY using the virtual prototype technology,taking the water-cooled gearbox of blast furnace as research object and the research of its dynamics simulation is carried out.The simulation results show,either in high or low speed rotation,the meshing force of the outer ring gear is comparatively small.Contrarily,when in tilt,the meshing force of the outer ring gear is comparatively large,the maximum meshing force is nearly 2times of the former,it is show that the distributing device is not very stable when the chute tilting.