Abstract: Research on routing in Low Earth Orbit Satellite Networks is a hotspot in areas of satellite communications， and how to secure routing algorithms has been attached increasing importance. After a terse analysis of security threats faced by on-demand routing protocols for satellite networks， a secure on-demand routing protocol is presented， which is on the basis of identity-based signcryption schemes and fit for the features of satellite network topology. According to the protocol’s characteristic of heavy time overhead in processing crypto algorithms， a mechanism called delayed verification with adaptive probability is designed for decreasing route discovery time. Security analysis and simulation experiments show that the proposed protocol can resist typical outside attacks and guarantee steady packet delivery ratio at the cost of finite increase in route discovery time and route overhead.