Based on the ranging principle of satellite laser ranging (SLR) system, the distribution of echo photon reflected back from the angle reflector is simulated numerically, and the relationship between the shape effect of the satellite angle reflector and the ranging precision of SLR system is analyzed and discussed. In addition, in order to verify the applicability of the shape effect of the satellite angle reflector, the satellites at different orbits are observed by the SLR system in Changchun Observatory, National Astronomical Observatories, Chinese Academy of Sciences. The results show that the shape effect of the satellite angle reflector has significantly changed the distribution of the echo photons reflected from the satellites, and the laser pulse width is broadened. For Starlette, the laser pulse width is extended from 50 ps to 72 ps, and the ranging error caused by the shape effect of the satellite angle reflector is about 5.4 mm. For the high-orbit Etalon-1 satellite, the middle-orbit Lageos-1 satellite and the low-orbit LARES satellite, the ranging errors are about 15.4, 7.4, 5.0 mm, respectively. Therefore, for the development of the measurement accuracy of SLR system to the mm level, the influence of the shape effect of the satellite angle reflector on the ranging precision should be considered, which also provides new ideas and approaches for the evaluation performance and structure design of SLR system.