The invention discloses a multi-circuit LED constant current driving circuit. According to the multi-circuit LED constant current driving circuit, currents of branch circuits of corresponding LED lamps are adjusted by virtue of a plurality of constant current control circuits, the voltages at control ends of transistors in the constant current control circuits are sampled, the maximum voltage is selected as a voltage feedback signal, and a switch control signal of a direct current converter is generated according to the voltage feedback signal and a reference voltage signal and is used for regulating an output voltage of the direct current converter to meet driving requirements of LED lamps on multiple circuits. By virtue of the technical scheme of the invention, the system loss can be greatly reduced; and furthermore, an IC can be designed by virtue of a low-voltage process, so that the system cost is lowered.