Abstract: During the entire work process, the frequency accuracy of input sine AC power directly affects the vibration of the linear Sterling refrigerator. Especially for single -piston linear Sterling refrigerators, the input sine AC electro -frequency accuracy will directly affect the vibration, reducing performance of the dynamic vibrator connected. Based on the research on the linear Stirling refrigerator inverter, through the analysis of the SPWM wave generation method, the MCU clock frequency in the inverter circuit, the cut-off frequency in the filter circuit, capacitance and inductance, etc., the relationship between the number of switches and frequency accuracy is obtained. According to the requirements of the actual application, the error between the actual output frequency of the linear Stirling refrigerator inverter and the target frequency must be less than ± 0.1Hz, and the frequency accuracy needs to be controlled within ± 0.1 %. Therefore, under this application conditions, when the MCU frequency is 72 MHz, the number of switches that meets the requirements is found to be between 1400-2400, and corresponding frequency accuracy is less than < ± 0.1%.