In addressing the issue of prolonged simulation time for Hierarchical Cascade Technology (HCT) in simulation of Surface Acoustic Wave (SAW) devices, as well as errors caused by numerical instability when using infinite long damping boundary (ILDB) conditions, effective numerical processing methods are needed to ensure efficient and accurate simulation results. Equilibrium preprocessing the finite element matrices of basic unit blocks, accelerating simulations with single-precision numerical computations, and employing LU decomposition when eliminating internal degrees of freedom could enhance the accuracy of simulation results when ILDB boundary conditions were used for single-precision simulations. Through simulation testing and comparative analysis on various Surface Acoustic Wave (SAW) devices, the optimized single-precision Hierarchical Cascade Technology (HCT) method proposed in this paper not only reduced simulation errors, but also reduced the simulation time by 50% compared with traditional hierarchical cascade methods. Furthermore, the proposed method was applicable to ILDB conditions. The approach developed in this paper holds significant importance for the rapid and accurate design of surface acoustic wave sensors.