In this paper, differential capacitors sandwiched structure of a high-G capacitive microaccelerometer with round metal proof mass supported by multi-beam and its characteristic are presented. The operation principle and built-in self-calibration and self-test functions are described. The fabrication process and the fabricated chip of the microaccelerometer based on UV-LIGA technology are reported. The detection and closed-loop control circuits of the microaccelerometer are designed and calibrated. The range of the detection channel is ±6pF, the sensitivity is 89.3mV/pF, and the linearity is 2.59%.