In order to measure the space angle of two non-uniplanar lines with a distance of several even tens of meters, the design proposal of a laser system for measuring the large-scale space angle formed by non-uniplanar lines was proposed. Firstly, in consideration of the existence forms of space angles formed by common targets, corresponding orientation methods were designed and a common reference in the space angle measurement was proposed. The single beam of linear structured light was used as the common reference when the distance of the targets was only large in the direction of common perpendicular. Then, the design process of a system framework applied in a specific project was analyzed. Finally, the inspection method of spatial relationship between the common reference and targets was proposed. With digital image processing, the angle between common reference and targets was measured, and the measurement result was acquired indirectly. In measurements for 30 times, the repeatability of the system is ±0.020 85°, which proves that the measurement system can satisfy the requirements of practical projects and the proposed principle is reasonable.