Recently, mega satellite constellations are very popular for global instant messaging, and inter-satellite links are planned for delay reduction, leading to satellite network architecture finally. Although there are many satellite orbit simulation tools (e.g. STK, Savi) and network simulation tool (e.g. NS2/3, OPNET, Mininet, SNS3), none of them gives good consideration to both. In this paper, a satellite network and orbit integrated simulation platform (Mini-Savi) is proposed for large scale satellite constellation, which is based on the combination of network simulation tool Mininet and orbit simulation tool Savi. Finally, a typical satellite constellation Iridium system is employed for simulation verification.