In low earth orbit (LEO), spacecrafts travelling through dense but low-energy plasma generate a wake zone behind. The TianXunⅠmicrosatellite is taken as the research object and SPIS toolkit is employed to simulate its surface charging,sheath structure and wake zone feature in LEO plasma environment. The simulation reveals firstly that TianXunⅠcan not charge to high level on its orbit. Secondly, it is found out that a phenomenon called plasma density enhancement and satellite sheath reveals significant difference from traditional satellite. The phenomenon of density enhancement occurs in the far wake region and can be explained by orbital motion limited (OML) theory. The sheath of microsatellite is abided by thick-sheath approximation in LEO and the thickness of sheath varies with surface charging level.