Aimed at the features of pA-level weak signal and strong background signals of the miniature electric field sensor, this paper designs a weak signal detection and calibration measurement system. Based on the visible program language Labview, this system can realize the sensor controlling and signal processing. In addition, through the new technique of correlation detection and background signal suppressing, it can achieve signal detection with a low SNR of -60 dB, and be capable of calibrating micro electric field sensor. By appending correlative measurement module, the static and dynamic parameters can be further detected, and the response curve can be plotted.