Abstract: A highly sensitive SAW voltage sensing mechanism based on thermoacoustic conversion is proposed and experimentally verified. Based on heat transfer and perturbation theory, the theoretical model of SAW voltage sensing based on thermoacoustic conversion mechanism is established, and the influence of structural parameters and environmental factors on the sensitivity of SAW voltage sensor is explored. In order to verify the theoretical model, MEMS micro heater and 200MHz SAW device are integrated with the chip on Y-cut quartz substrate to prepare SAW voltage sensor components, and voltage test platform is built to test the performance of sensor components. The experimental results show that there is a quadratic linear relationship between the voltage and frequency response of the prepared SAW sensor, and the voltage sensitivity (22.4kHz/V) at room temperature (20゜C) is close to that of the theory. In addition, the influence rule of ambient temperature on the voltage sensitivity obtained by the experiment is consistent with the theory. The SAW voltage sensor based on the thermoacoustic conversion mechanism can significantly improve the sensitivity of voltage detection.