The invention relates to a real-time measurement system for surface potential changes of insulating materials. The system includes base, probe and electrode fixing bracket, slide rail ruler, probe holder, support column, high voltage electrode, ground electrode, capacitance probe, probe protective cover, insulating material fixing groove, electrostatic voltmeter, data acquisition system, And a data processing system and a display interface. Among them, the fixed bracket of the probe and the electrode is fixed above the base through the support column, and the sliding guide rail is set on the fixed bracket. The ground electrode is fixed on the base, the insulating material fixing groove is opened on the base, and the electrostatic voltmeter, data acquisition module, data processing system and display interface are connected in sequence. The invention can realize on-line real-time measurement of surface potential of different solid insulating materials and similar solid insulating materials after surface modification under DC voltage and after power off.