We developed high-efficient 6W-LED package with simple structure by applying Heat Slug and silicone-reflector. LED package was manufactured in $8.5{ imes}8.5mm$ sized multi-chip structure having thickness of $500{mu}m$ achieved by bonding silicon-reflector with prepreg on top of the plate after implementing the reflector placed on copper substrate Half Etching by thickness of $200{mu}m$. The luminous flux, luminous efficacy, correlated color temperature, color rendering index and thermal resistance of developed LED was evaluated, and it verified the application of products by applying it to 120W-LED road luminaires through simulation. The luminous efficacy of LED package reached over 130lm/W, and it is possible to be manufactured into 120W-LED road luminaires using 18 packages. In addition, the simulation results showed average of horizontal illuminance and overall illuminance uniformity that is suitable for three-lane road.