High-temperature vibration monitoring is essential for failure diagnosis and equipment maintenance. This paper presents a La3Ga5 SiO14(LGS) surface acoustic wave (SAW) high-temperature vibration sensor based on the symmetrical structure of four-end fixed beam, capable of withstanding temperatures up to 800℃ and providing high sensitivity and wide band by using an optimized algorithm. Then the mathematical model of SAW vibration sensor with a four-end fixed beam was constructed, and the sensitivity and natural frequency of the sensor were analyzed. Subsequently, the structural model of the sensor was established, and the mechanical and electrical simulations were carried out in the range of 20℃ ~800℃, which reveals the mechanical and electrical properties of the sensor at high temperature. The results show that the sensitivity of the proposed sensor in this study is about 7. 047 times higher than that of the sensor with single SAW resonator, and the sensitivity increases progressively with temperature at 20℃ ~800℃, reaching 9. 879 1 ×10 -6 / g at 800℃. The natural frequency decreases with temperature, showing 3 018. 4 Hz at 800℃ . Finally, the feasibility of the design was preliminarily verified by experiments, which provides a new idea for the optimization design and high-temperature application of SAW vibration sensor.