Abstract: The laser scribing process for a-Si (amorphous silicon) thin film solar cell preparation requires the line width of 30 m～50 m, the dead zone of less than 300 m in size, and the compliance of line depth with the process requirements. Thus, the high beam quality of the laser is required, as well as the high imaging quality and wide focal depth of the optical system. A laser scribing system with a single laser and fourway light splitters was designed. With the designed laser scriber, a laser scribing test was done on a 1 400 mm1 100 mm3.2 mm glass substrate. The widths of the scribing lines P1, P2 and P3 were 35 m, 50 m and 45 m, respectively, the dead zone (distance between P1 and P3) was 287 m, and their final depths were 0.98 m, 0.24 m and 0.58 m respectively. The results show that the widths and depths of the scribing lines meet the requirements of thin film solar cell preparation process.