Abstract Over space optical communications are considered as the critical technology for high-bandwidth, high-speed, and large-capacity communications. Indeed, the laser wavelength’s narrow beam divergence requires a precise beam pointing at both ends of the optical link. The precise beam pointing makes the laser beam pointing to or from a moving object is one of the most challenging processes for optical space communications. In this work, the effect of the pointing error due to satellite platform vibration over the performance of the laser communication link of the optical inter satellite network (OISN) system in terms of the quality factor is investigated. Indeed, an optical communication system has been built using the OptiSystem program to simulate the link between satellites in space for the OISN system. In addition, the proposed system shows by simulation the optimal parameters’ values required for the design of the optical communication link between satellites of the OISN system. Moreover, the effect of pointing error due to the platform vibration on the performance of the OISN system is investigated for different scenarios of the pointing error (i.e., no pointing error; one side of the link with pointing error, and two sides of the link with pointing error). The simulation shows that, first, the optimal parameters that can be used for the optical communication link between satellites of the OISN system in terms of the laser wavelength; laser power; optical modulation scheme; optical telescope aperture diameter; and telescope optical efficiency. In addition, the simulation shows that existing pointing error due to vibration at one side of the optical link leads to degradation of the performance of the OISN system in terms of the quality factor for different laser beam power; distances between satellites; telescope diameters; and telescope efficiencies. Moreover, existing pointing errors at the two sides of the optical link lead to rapid degradation of the considered OISN system performance even with the increase of the laser power or telescope diameter, which tend to compensate for its effect initially and then quit.