At present, the primary and secondary deep fusion sensor apply in the field of distribution network automation more and more popularly. In order to realize the traceability of the weak output AC sensor and establish the corresponding error check system, the active capacitive voltage divider is developed as a standard device in this paper. A precision voltage matching unit is designed to solve the problem of voltage unmatching between the standard device and the sensor under test. Through the multi-stage shielding structure, secondary series boost coil and dynamic following feedback circuit, the inverse and proportional boost functions of precision voltage matching unit are realized. The error analysis and test are carried out by self-calibrating single-disk induction voltage divider. Finally, the error calibration of weak output voltage sensor is realized with active standard and error measurement system.