In this paper, a novel triaxial SAW acceleration sensor is proposed. The model of the sensor is established and the finite element simulation is carried out. The displacement and strain distribution of the sensor structure under different acceleration loads are obtained. The sensor design adopts a four-terminal five-beam structure. The influences of temperature drift on the response of x and y axial acceleration sensors are eliminated and the decoupling of each axial acceleration is realized through the design of the resonator position and the algorithm. The feasibility of the overall design of the proposed three-axis acceleration sensor is verified from theory and simulation. The modal analysis of the sensor is carried out to obtain the natural frequency of the sensor to avoid the resonance damage. The results show that the modal analysis of the sensor structure provides a certain basis for avoiding the damage to the sensor in practical application.