The present disclosure is for a light-emitting diode light string control system, which comprises: a switching unit having a power input end, a power output end connected to the light string, and a controlled end. A control unit is connected to the controlled end of the switching unit. A second power-generating unit is also connected to the light-emitting diode light string. The light-emitting control command sent by the control unit is in a carrier wave mode to realize brightness variation of the light string, which saves costs and simplifies the control circuit. A short-circuit protection unit is employed to provide fast and reliable response in real time.