Abstract: Imemal charging effect is one of the main causes of spacecmft night fault. According to the requirement of the ground simulation experiment with respect to the intemal charging effect, a charge measurement method based on the Vibration capacitance method is proposed. The physical stmcture of the sensor and the signal pmcessing circuit are designed. The prototype of the measuring instrument is developed, and calibrated by test. The test results show that the instmment features high linearity, good accuracy, and stable performance.