In view of the characteristics of satellite link in space laser backbone network using advanced orbiting systems(AOS) frame for data transmission, limited on-board resources and long data transmission delay, in order to realize label switching and traffic engineering in satellite optical networks, the standard route based restricted label distribution protocol(CR-LDP) is impro-ved, including setting a fixed length for the size of protocol messages, designing a connectionless transport layer protocol, reducing protocol overhead and improving the establishment process of bidirectional label switching path(LSP), and then the software simulation and hardware test are carried out. The results show that the improved CR-LDP protocol has less resource consumption, supports bidirectional LSP establishment, and the process is simple and effective.