The present invention provides a method for manufacturing an LED light bar and an LED light bar thereof. The method includes (1) providing a metal substrate (20) and a plurality of LED lights (40); (2) forming a graphene layer (60) on the metal substrate (20) in such a way that the graphene layer (60) includes hollow sections (62) formed to correspond to the LED lights (40); (3) mounting the LED lights (40) to the metal substrate (20) in the hollow sections (62); and (4) forming silicone layers (80) in the hollow sections (62). The method for manufacturing the LED light bar and the LED light bar thereof according to the present invention use a graphene layer formed on a metal substrate and use silicone layers for planarization and heat transfer so as to effectively enhance heat dissipation performance of the LED light bar and extend lifespan of the LED light bar.