As a new energy conversion device that can convert mechanical energy into electrical energy, triboelectric nanogenerator has attracted extensive attention since its invention. However, its environmental performance is limited because the raw materials are mostly synthetic polymer materials. Using green and environmentally friendly cellulose materials to prepare triboelectric nanogenerators is one of the important ways to solve the above problems. In this study, cellulose/barium titanate composite paper is prepared by using bamboo cellulose and barium carbonate (BaTiO₃) as raw materials and combining wet papermaking and doping modification. The paper based triboelectric nanogenerator (C/BT-TENG) is constructed by using the cellulose/barium titanate composite paper as a positive friction layer. The results show that the addition of BaTiO₃ significantly improves the relative dielectric constant of the composite paper, and the output performance of C/BT-TENG increases with the augment of BaTiO₃ doping amount. When the doping amount is 4%, the open-circuit voltage and short-circuit current of C/BT-TENG reach the maximum values of 118.5 V and 13.51 µA, respectively, which are 51.3% and 41.2% higher than when pure cellulose paper is used as the positive friction layer. The mechanism of dielectric regulation to improve the C/BT-TENG output performance is analyzed by the modeling method. In addition, the C/BT-TENG has a good output performance and operation stability. When the load resistance is 5 MΩ, the maximum output power density of C/BT-TENG reaches 0.36 W/m², simplying a good application prospect.