Abstract: A scheme of Capacitance Diaphragm Gauge (CDG) based on MEMS technology was proposed. The simulation model was established using finite element analysis software, and the size of the diaphragm and the distance between electrodes were optimized. According to the optimization results, a differential CDG was developed, and its performance was tested. Results show that the measurement range covers from 5 Pa to 1 000 Pa, the sensitivity is better than 10fF/Pa, and the test curve is piecewise linear.