The invention discloses a method for processing plant-based waste residue by utilizing cellulose and combining mechanical expression. The method comprises the following steps of uniformly mixing cellulose and plant-based waste residue, and placing the mixture at a room temperature, or preserving the temperature of the mixture for certain time, squeezing the uniform mixture by mechanical expression equipment so as to filtering the liquid part out, and drying the rest of the dry material by steam, and finally combusting the dried material. By adopting the method for processing the plant-based waste residue provided by the invention, more than 80 percent steam consumption is saved compared with that of the conventional processing method in which the plant-based waste residue is combusted after being directly dried by steam, and meanwhile, the processing time is shortened, and the production costs of manpower, electric power and the like are reduced.