This study is divided into two parts. The first thing to understand is that the lamp choice is energy saving light. Also, use effective lighting design and control system can avoid energy waste. Only periodically lamp maintenance can keep comfortable lighting environment. We use DIA Lux optical design software to stimulate the lighting in commercial buildings. The design analyzing processes are as follows: (1) set up lamp types; (2) set up the placement of the lamps in each floor; (3) set up the placement of the desks; (4) set up the material coefficient of desks, floor and ceiling; (5) practice optimum optical simulation and evaluate whether the optical quality can achieve the design target.