Abstract: The electrostatic servo MEMS capacitance diaphragm vacuum gauge has wide range and high stability, and has broad application prospect. The measurement circuit is the key factor to ensure the performance of the electrostatic servo MEMS capacitance diaphragm vacuum gauge. A micro capacitance detection circuit is designed by using AC excitation detection method, and verified by software simulation and experiment. The results show that the circuit can quickly detect small capacitors and convert them into DC voltage signals with a resolution of 0.33 V/pF. In addition, the anti-drive voltage interference test shows that the circuit can work normally at DC drive voltages in the range of 1 ~ 100 V, and the maximum variance of capacitance measurement is 0.010249 V, which has excellent stability.