Aiming at the accurate and rapid design of surface acoustic wave (SAW) filter with any complex film structure and the circuit topology, the hierarchical cascade model(HCT) is used to optimize and design the trapezoidal resonator and the dispersive COM model is used to optimize and design the longitudinal coupling resonators, based on the full-wave simulation platform of acoustic/electrical/magnetic multi-physical field coupling, combined with the genetic optimization algorithm and general graphics processor(GPGPU) acceleration technology. The forward design and optimization of SAW filters with arbitrary complex film structure and circuit topology are realized. The optimization design and development of a 42° Y-X LiTaO3 conventional SAW filter were carried out, and the design optimization results were in good agreement with experimental results, verifying the effectiveness and feasibility of the proposed method.