The research direction is to apply the precision machining and the micro-electroform technology on LCD back light module (BLM). The goal is to strengthen the BLM energy utility, increase the BLM brightness, and save the material cost. In experiments we adopted the ultra precise machining and the micro-electroform technology in the LGP mold processing in order to enhance the BLM brightness. Since both technologies are different from the commonly used etching processing way, therefore, this study will be aimed at the analysis on three different processing technology in LGP. Consider the general LGP reflecting surface as the etching way is the base-line data for BLM average brightness, the change of reflecting surface is the V-cut processing way. After injection the reflecting surface of LGP is convex V-cut that may increase 6% brightness in comparison with the etching way. However, the application of the micro-electroform way of injection the concave V-cut LGP may again promote 6% brightness in its optics performance. Therefore, the increase of micro-electroform processing, the BLM brightness promotes approximately 12% compared to the etching way. That may reduce the lens use of the BLM and achieve the economic efficiency in cost redution.