The invention discloses a constant current comparison circuit for an LED driving circuit. The constant current comparison circuit for the LED driving circuit comprises a first sampling resistor, a second sampling resistor, a first gain adjusting module, a second gain adjusting module, a first indication module, a second indication module and a voltage amplification module. The constant current comparison circuit for the LED driving circuit respectively samples voltages of a first LED lamp set and a second LED lamp set through the first sampling resistor and the second sampling resistor, the sampled voltages are inputted into the voltage amplification module, the first gain adjusting module and the second gain adjusting module which are connected with the voltage amplification module can adjust amplification gain of the voltage amplification module, so enough great voltages can be provided to enable the first indication module and the second indication module to display a voltage difference of the first LED lamp set and the second LED lamp set, and thereby the lamp set of the first LED lamp set and the second LED lamp set which has a higher current can be determined.