Abstract: In order to meet the requirements of high precision measurement of satellite load pointing, a space load pointing measurement system was designed based on laser position sensitive detector (PSD). The principle was as follows: a laser beam was transmitted to the reflector installed on the load, and then it was reflected to the photosensitive surface of the PSD; a photocurrent was generated by the PSD sensing laser light; after current to voltage conversion, the signal was outputted to a high-precision acquisition controller, in which data was processed using algorithm to obtain the small angle change of the load pointing. The test results show that the measurement angle range of the system is ±0.15°; the measurement accuracy of pitch and tilt angles is within 0.002°; and the measured angle stability is better than 0.000 4° within 3.5 hours. The system may not only meet the requirements of small angle rotation measurement of load pointing caused by thermal deformation and other factors in orbit, but also meet the requirements for small angle and high precision measurement in ground testing.