Our company's cable partial discharge online monitoring system utilizes a modular design approach. It employs high-frequency pulse current sensors installed on the grounding wires of cable joints to couple the partial discharge pulse current signals from the cable body and the joint. The coupled pulse current signals are transmitted to the front-end monitoring collector via coaxial cables. After amplification, filtering, and analog-to-digital conversion of the analog signals, they are converted into digital signals and transmitted to the back-end server via optical fibers. The back-end server classifies, identifies, and analyzes the signals from all sensors, writes the discharge information data obtained from the calculations into the database, and simultaneously displays the monitoring results on the software of the monitoring system.