The invention discloses a loop resistor detection system and method based on a supercapacitor set. The system comprises a collection control module, a computer, a voltage stabilizing power source, a voltage controllable constant current charger, an isolation control module, an isolation measuring module, a current shunt, a silicon controlled rectifier and the supercapacitor set, wherein the computer is connected with the input end of the collection control module; the output end of the collection control module is connected with the silicon controlled rectifier and the voltage controllable constant current charger through the isolation control module, and the voltages at the two ends of the current shunt, the two ends of a loop resistor and the two ends of the supercapacitor set are collected through the isolation measuring module; the silicon controlled rectifier, the loop resistor, the supercapacitor set, the voltage shunt and the voltage controllable constant current charger form aseries connection loop, the voltage controllable constant current charger is connected to the 220V alternating current network, and the voltage stabilizing source supplies power to the collection control module and the isolation module; the collection control module controls the current shunt through the isolation module.