Abstract: According to technical requirement of KM6 solar simulator optical adjustment system, two kinds of schemes are putted forward to collimate semiconductor laser beam. The scheme of foreground collimating optical system is adopted as the principles of two technical schemes are introduced and compared. The design of optical system, analysis of the imaging quality of optical system, design of the mechanical structure for optical system, and analysis of the collimation character of collimated laser beam are introduced. The results show that qualification of the semiconductor laser collimator is better than that available, which beam angle of divergence is 5～8 mrad, and therefore the adjusting work of KM6 solar simulator optical system can be going on.