Method and circuit for controlling multi-path current distribution of LED power supply

The invention discloses a method and a circuit for controlling multi-path current distribution of an LED power supply. The method comprises the following steps of: S100, presetting a current threshold and an MOS voltage drop threshold; S110, switching on an MOS transistor; S200, detecting the current of each LED lamp group, judging whether a current value which is less than the threshold exists or not, if so, executing S300, and otherwise, executing S400; S300, controlling an AC-DC module to boost the LED lamp groups through an optocoupler feedback control circuit, so that the current values of all the LED lamp groups are more than or equal to the set current threshold; S400, reducing the current of the LED lamp groups of which the current values are more than the set threshold through a control module, so that the current value of each LED lamp group is equal to the preset current threshold; and S500, performing voltage drop detection on the MOS transistor on each LED lamp group through the control module, controlling the AC-DC module to reduce the direct-current output voltage of the MOS transistors of which the voltage drop is more than the set threshold through the optocoupler feedback control circuit, and executing S200. The method can effectively solve the problems of light equation and optical attenuation and greatly improve the efficiency of the circuit.