Satellite communication networks have many outstanding advantages over traditional communication systems, such as terrestrial cellular networks, and will play a central role in next-generation wireless communication systems. Low-orbit satellite communication systems have great potential and value due to their advantages such as lower transmission delay and higher communication quality. However, due to the dynamic nature of satellite constellation topology, load imbalance and node/link failure problems, the design of routing algorithms puts forward high requirements. This paper analyses the inclined orbit topology characteristics of low earth orbit (LEO) satellite network and the influence of phase factor according to the characteristics of LEO satellite network, and on this basis, analyses the advantages and disadvantages of the existing routing protocols in conjunction with the challenge of the design of routing algorithms for LEO satellite network.