The invention discloses a preparation method of ZnS/Si nuclear-shell nanowires or nanobelts and polycrystal Si tubes. The preparation method comprises the following steps: carrying out two-step thermal evaporation in a vacuum tubular furnace, synthesizing the ZnS/Si nuclear-shell nanowires or nanobelts with different diameters by taking ZnS with different shapes as templates and controlling the growth time of Si, and processing with diluted hydrochloric acid to obtain the polycrystal Si tubes with multiple shapes and different diameters. The preparation method is simple to operate, has good controllability, and is suitable to large-scale production of the ZnS/Si nuclear-shell nanowires or nanobelts and polycrystal Si tubes, with multiple shapes and the different diameters. A one-dimensional nano material obtained with the method in the invention has a wide application prospect in the aspects of silicon-substrate integrated circuits, nano optical devices, nano sensors and the like.