Surface acoustic wave (SAW) based accelerometers have received significant attention due to their digital output, low cost, mass production and easy implementation of wireless passive function. However, conventionally rectangular cantilever-beam based SAW accelerometers often have non-uniform strains generated along the beams, which cause emergence of parasitic wave modes and measurement errors. In this paper, a simulation platform was developed to analyze and optimize designs of SAW accelerometers and variable-thickness and equal-strength beams were designed to solve the critical issue of non-uniform strain distribution along the beam. Frequency responses of SAW accelerometers under the acceleration were successfully obtained using the simulation platform, with the visualized strain/stress distribution and particle displacement field. The accuracy of this simulation platform was verified using the experimental result reported in literature. A highly sensitive and equal-strength beam SAW accelerometer was achieved with a sensitivity up to 1.40 kHz g−1, a linearity coefficient of ∼1, and a measurement range of 0∼15 g. Furthermore, a high-G accelerometer was designed, with the capability of enduring large shocks up to 11,500 g and a sensitivity of 6.96 Hz g−1.