The utility model provides a pair of online power equipment monitoring system's power supply system, include: get ability mutual -inductor CT1, rectifier circuit Z1, overvoltage crowbar, a power supply circuit, the 2nd power supply circuit, stand -by power supply and treatment circuit, get can the mutual -inductor CT1's induction coil's both ends be connected with rectifier circuit Z1's positive input terminal and negative input end respectively, rectifier circuit Z1's forward transportation output and a power supply circuit's input are connected, rectifier circuit Z1's negative output termination ground, an output of the power supply circuit 12V direct current, a power supply circuit's output still is connected with the 2nd power supply circuit's input, the 2nd output of the power supplycircuit 5V direct current, stand -by power supply's input and the 2nd power supply circuit's output are connected, stand -by power supply's output and treatment circuit point connection, stand -by power supply still is connected with processing circuit communication, overvoltage crowbar sets up the route between a rectifier circuit and a power supply circuit, the control output of treatment circuit still is connected with overvoltage crowbar, can export two kinds of galvanic currents.