The invention relates to the field of processing of tobacco products, in particular to a tobacco slice and a preparation method thereof. The tobacco slice is prepared by taking a non-tobacco plant as a raw material, immersing the plant raw material by using hot water, separating a solid substance from an extract, dissolving the extract by using 80 percent of ethanol, settling at low temperature, concentrating the clear liquid, coating the concentrated liquid onto a slice base made of wood pulp, and then drying. The slice does not contain any nicotine, replaces partial tobaccos and is added into cigarettes or cigars to effectively reduce harms caused by harmful substances, such as oil tar, nicotine and the like in the smoke, to human bodies. The raw material has effects of moisturizing thelung, stopping cough, clearing heat and detoxifying, and can improve the discomfort caused by smoking on the throat and the lung to a certain extent; meanwhile, the tobacco slice has a unique naturalherb and / or woody plant flavor and can be well coordinated with the tobacco flavor; and the tobacco slice is a specialized low-harm raw material during production of tobacco products.