The invention relates to a preparation method of a high-performance sisal hemp nanocellulose membrane-based friction nanogenerator, which belongs to the field of novel nanomaterials, energy collection and self-powered sensing, and comprises the following steps: (1) pretreating sisal hemp fibers through hydrothermal reaction; (2) carrying out alkalization and etherification reaction on the sisal cellulose to obtain sisal carboxymethyl cellulose; (3) bleaching and hydrolyzing the sisal cellulose to obtain sisal microcrystalline cellulose; (4) adding the sisal hemp carboxymethyl cellulose into the sisal hemp microcrystalline cellulose to prepare a sisal hemp nano cellulose membrane; and (5) assembling the sisal hemp nano cellulose membrane and a friction electronegative material to prepare the friction nano generator. The sisal fiber is used for preparing the sisal nano-cellulose membrane, the raw material source is wide, the manufacturing cost is low, the sisal nano-cellulose membrane is used as a triboelectric positive electrode material and assembled into the triboelectric nano-generator, high electric output performance is obtained, and a new thought is provided for self-energy supply of wearable electronic equipment in the future.