Tooth surface wear, recognized as a major contributor to gear failure, significantly compromises the performance and service life of transmission systems. Current studies on gear wear and dynamics frequently fail to account for the continuous evolution of tooth surface morphology and the elastic-plastic nature of contact conditions. This limitation leads to inadequate accuracy in predicting both wear accumulation and the dynamic behavior of the system. To address this issue, we formulated a predictive model for tooth surface wear and a gear dynamic model based on fractal contact theory. This framework enables accurate simulation of wear progression on gear surfaces and elucidates the influence of wear accumulation on the dynamic behavior of the transmission system. The study aims to enhance the comprehension of gear wear mechanisms and provide a theoretical basis for condition monitoring and intelligent maintenance of wear-degraded gear systems.