With the rapid development of satellite technology and rocket carrying capacity, LEO(Low Earth Orbit) satellite broadband communication system equipped with inter-satellite laser communication technology has become a new trend. In order to maintain the accurate initial alignment and establish the link for inter-satellite laser communication, ensure the stable signal transmission, reduce signal loss and interference, and improve the quality and reliability of communication, the process of initial alignment for inter-satellite laser communication is analyzed, and a new ephemeris format and ephemeris broadcast format under the overall consideration of satellite resources is proposed in this paper. A highly reliable communication bus has been designed according to the communication requirements, giving full consideration to various working conditions in the process of inter-satellite laser link establishment process, which has greatly improved its achievement ratio and reliability. The results of on-orbit application prove that the design scheme is reasonable and feasible, which can guide the laser communication terminal to complete the initial alignment efficiently and rapidly, and realize the long-term stable chain building with the aid of ephemeris data, and has great significance for the future research and application of LEO satellite communication network.