ZnS thin films were prepared on silicon substrates by magnetron sputtering technology, and the effect of sputtering power on the deposition rate, surface roughness and surface morphology of ZnS thin films was investigated. The surface morphology, microstructure and optical properties of the films were characterized by step profiler, atomic force microscope (AFM), scanning electron microscope (SEM), ellipsometer, etc. The results show that the deposition rate of ZnS thin films is related to the sputtering power, and increases linearly with the increase of sputtering power; the surface roughness of ZnS thin films is related to the sputtering power and shows a trend of increasing first and then decreasing with the increase of sputtering power. In terms of microstructure, the grain size of the film also shows a trend of increasing first and then decreasing. With the increase of sputtering power, the refractive index of the ZnS film layer first decreases and then increases. Therefore, the sputtering power plays an important role in the growth of the film layer.