The irradiation effect of fast neutrons(1.2 MeV) on Gallium Nitride(GaN) white Light-Emitting Diodes(LEDs) with fluence of 1×1014 cm -2 is reported. The Electroluminescence(EL) spectrum, output power-current(L-I) and current-voltage(I-U) characteristics of the device are measured and analyzed. It is found that the optical output power decreasing after irradiation, while the shape of the EL spectrum almost remains unchanged, indicating that the neutron irradiation mainly causes damage to the blue LED chip. Further analysis shows that neutron irradiation leads to the generation of a large number of nonradiative recombination centers in the quantum well, which increases the leakage current and decreases the carrier density, thus reducing the output power of LED. In addition, the influencing factors caused by neutron irradiation are added to the original equivalent circuit model of GaN-based LEDs. This model not only helps to understand the mechanism of the degradation of the neutron irradiation on the LED output power, but also provides a feasible method to predict the change of the output power after irradiation.