The invention relates to a preparation method for a preparative thin layer chromatography (TLC) silica gel plate with a layer thickness of 0.5-2.0 mm, and belongs to chromatographic separation technology. The preparation method comprises steps of uniformly mixing a TLC silica gel and a novel adhesive; coating the resulting mixture on a glass substrate, an aluminium foil substrate or a terylene substrate through a coater; putting the coated substrate into a drying oven and carrying out a drying process to prepare the TLC silica gel plate. The TLC silica gel plate has advantages of a layer thickness of 0.5-2.0 mm, a flat and smooth substrate surface, strong green light, a uniform and firm thin layer, no crack, no shallow crackle, no falling off, autonomic regulation of the layer thickness between 0.5-2.0 mm, a nonparallelism less than or equal to 0.02 mm, a qualified rate higher than or equal to 99.5%. The silica gel plate is used under normal temperature and pressure, and has advantages of simplicity, fastness and high efficiency. The silica gel plate is widely applicable for a plurality of fields such as drug industry, biotechnology, biomedicine and biochemistry, energy, food, cosmetics, environmental science, natural product chemistry.