As a result of the thermal deformation and mechanical vibration on satellite structure, the payload’s pointing regarding to the precision standard will be rotated with a small angle. In this background, a measurement method based on laser Position Sensitive Detector (PSD) technology for this purpose was suggested and a prototype was developed. This method uses unparallel double-beams, double light sources, double mirrors, and double sensors. And the measuring device has compact structure, small volume, light weight, and flexibility for layout. This experiment result shows that the measuring system is very suitable for satellite application and can meet the measurement requirement.