Tobacco extract as well as preparation method and application thereof

The invention relates to a tobacco extract as well as a preparation method and application thereof. The preparation method of the tobacco extract comprises the following steps: drying and crushing a tobacco raw material, uniformly mixing with an alkaline aqueous solution, extracting, and filtering to obtain a filtrate and a filter cake; concentrating the filtrate, adjusting the filtrate to be acidic, uniformly mixing the filtrate with an alcohol solvent, performing solid-liquid separation after complete reaction, and retaining liquid to obtain a nicotine salt solution; concentrating the nicotine salt solution, adjusting the nicotine salt solution to be alkaline, adding an organic solvent, extracting, retaining an organic phase, and rectifying and purifying to obtain nicotine; uniformly mixing the filter cake with an organic solvent, performing extraction, retaining a liquid phase, performing solid-liquid separation, retaining clear liquid, performing decompression treatment, and recovering the solvent to obta