The invention discloses a preparation method and application of sugarcane refined cellulose of tobaccos. The preparation method takes begasse as raw materials; the begasse is crushed and then pre-hydrolyzed, cooked with a caustic soda method and bleaching; and the materials are subjected to alkali refining treatment to prepare the cellulose. The cellulose is added into tobacco stem pulp and waste tobacco pulp, and then the mixture is used for making paper to obtain a regenerated tobacco leaf paper base with good quality. A scientific whole process is provided and a process including acid prehydrolysis, alkaline cooking and three-section bleaching is adopted to prepare the refined sugarcane cellulose with the content of alpha-cellulose of more than 90% in a separation manner. The obtained refined sugarcane cellulose has a good application effect in the aspect of the preparation of regenerated tobacco leaves and the whole quality and oral cavity comfort of the regenerated tobacco leaves adopting the cellulose have obvious advantages.