The irradiation influences the properties of GaN. We studied the irradiation of n-type, p-type, and i-type GaN with 2.9865GeV Ta ions, with experimental irradiation fluence of 3×108, 3×109, and 2×1010 cm-2, respectively. Low fluence ion irradiation of GaN enhances the luminescence performance of the samples and releases stress between GaN and the sapphire substrate. We have proved that this is due to the displacement of Ga or N atoms repairing the defects caused by the entry of irradiated ions, thus enhancing the performance of GaN. This provides a reference for low fluence irradiation of GaN.