Abstract: An AC LED module having surge protection function includes: an insulation seat, formed with a first surface and a second surface, wherein a concave area is formed on the first surface, and an opening is formed at a substantially central portion of the concave area; an annular fasten member, fastened in the concave area of the insulation seat, and formed with at least one buckle structure for being combined with a reflection cup; a circuit board, installed with a LED light source, wherein the circuit board is fastened on the second surface of the insulation seat, and the LED light source is aligned with the opening; and a surge absorbing member, disposed at the exterior of the insulation seat and electrically coupled to an AC power input port of the circuit board, thereby preventing the circuit board from being damaged by an AC surge.