Abstract: As a typical advanced laser, spaceborne solid state laser is one of the key components used in spaceborne laser altimetry systems. The requirement and working condition of spaceborne laser altimetry determine the technical characteristics of this kind laser source. The spaceborne solid state laser integrates the advanced, high reliable, light weight technologies and mature process, thus can meet the specific requirements of laser altimetry used in space environment condition. The development of high reliable laser resonator technology, high repetition rate narrow pulse width micro-pulse multi-beam laser technology, LD/fiber/solid-state integration technology for spaceborne laser altimetry and the current challenges were reviewed and analyzed, the significant breakthrough of multi-beam laser for spaceborne single photon scanning ladar system was proposed. At last, the development trend of spaceborne laser were summaried.