Numerical simulation has been carried out concerning the temperature frequency characteristics of a surface acoustic wave (SAW) sensor with ANSYS software. The internal temperature distribution of delay line surface acoustic wave sensor with Si/AlN/Al structure was analyzed under a certain pressure. The results show the effect of natural convection on the temperature field and stress field distribution in the sensor is small. The relationship between the temperature and the output resonant frequency is also simulated. According to the data fitting

the output series resonant frequency of the SAW sensor has a good linear relationship with the environmental temperature

so it can be used in the precise measurement of the temperature.