The invention discloses a GaN-based LED (Light Emitting Diode) having a nano-sized SiO2 grating passivation layer, and a processing method thereof. The GaN-based LED comprises a substrate and an epitaxial layer, wherein the epitaxial layer comprises an AIN nucleation layer, a GaN buffer layer, an n-type GaN layer, an InGaN/GaN superlattice layer, an In0.16Ga0.84N multiple quantum well layer, a p-AlGaN/GaN electronic blocking layer and a p-type GaN layer; a part of the epitaxial layer is etched to the n-type GaN layer, an un-etched part of the epitaxial layer forms a comb-shaped raised structure, the etched part of the epitaxial layer forms a comb-shaped groove structure matched with the comb-shaped raised structure; the p-type GaN layer is provided with an IOT layer, a SiO2 passivation layer and a P electrode thereon, the exposed n-type GaN layer after etching is provided with an N electrode, the SiO2 passivation layer is deposited between the N electrode and the n-type GaN layer, theSiO2 passivation layer is deposited on a sidewall of the raised structure; the ITO layer and the SiO2 passivation layer have graphical through-hole structures of which shapes are evenly distributed along the P electrode or the N electrode. The GaN-based LED of the invention has the beneficial effects that: the surface of the LED is protected, generation of a leakage current is limited, at the sametime, a current is expanded, current gathering is reduced, and luminous efficiency is improved.