A light-emitting diode driving system for transmitting a signal based on a power line comprising a switch unit, a control unit, a main power supply, and a secondary power supply, wherein the switch unit comprises a main input end, a secondary input end, an output end, and a controlled end. When the control unit is in an operating state, the switch unit is turned on. When the control unit outputs a high level signal to control the switch unit to be turned on, the main power supply outputs a main direct current power source to the switch unit, and when the control unit outputs a low level signal to control the switch unit to be turned on, the secondary power supply outputs a secondary direct current power source to the switch unit. The system can make the light emission effect of the light string more stable.