Triboelectric nanogenerators (TENGs) are a novel technology for harvesting environmental micro/nanoenergy to produce electricity. The electric field generated by different electrode properties of materials plays a crucial role in regulating the dynamic behavior of triboelectric charges between the dielectric layer and the metallic electrode. In this work, a model of dual-electric field mutual inductance TENG (DEF-TENG) is proposed, which aims to systematically study the effect of electric field mutual inductance of bilateral motors on the amount of charge in the TENG. The changed state of the dynamic electric field is obtained through theoretical analysis. By introducing an external charge from the metal, the model strengthens the effect of bilateral electric field mutual inductance, thereby improving the ability of the metal electrode surface to carry the charge and establishing a new dynamic equilibrium of triboelectric charge. The relationship between the structural parameters and the electric field mutual inductance is analyzed by deriving the theoretical formula of the DEF-TENG. The experimental results show that the open-circuit voltage and the transferred charge of the DEF-TENG are 156% and 154% higher than those of a single-electric field TENG (SEF-TENG) after introducing external charges. This study provides a novel method and guidance for linear-to-rotary triboelectric nanogenerators to improve power generation.