The fast growth of communication technology has resulted from the desire for information globalization. Satellite communication systems, which have the benefits of extensive coverage and minimal requirements on the geographical environment as compared to terrestrial communication systems, are progres-sively becoming the principal competitive arena of next-generation communi-cation. The low-orbit (LEO) communication satellite has a high data transmis-sion rate, a short communication latency, and a near proximity to the earth. The conventional geostationary orbit communication market has worsened as a re-sult of the fast expansion of terrestrial communication technology and Internet technology, and the development of low-orbit satellite communication has be-come a general trend. Satellites with the same tasks are getting smaller and smaller, and the cost is getting lower and cheaper, thanks to the rapid growth of the integrated circuit industry. Furthermore, the new technology represented by the reusable rocket can cut the cost of launching a LEO satellite even further, making the development of a LEO communication satellite network more af-fordable and viable. In comparison to the terrestrial communication network, the LEO satellite network can provide communication services that span the whole globe and can support communication in distant places, mountainous areas, and maritime areas at a reduced cost. At the same time, the LEO satellite network differs significantly from the terrestrial network in several ways. This research is a survey paper that focuses on routing protocols algorithms for LEO constellations networks, to the best of our knowledge.