Abstract: In order to ensure the safe storage of low-temperature propellant in orbit and improve the efficiency of active pressure control system,it is very important to research on the configuration and deformation characteristics of vapor region under microgravity.In this paper,the volume of fluid(VOF)method is used to numerically simulate the deformation characteristics of the gas-liquid interface in a cryogenic liquid propellant tank under microgravity conditions and the influence of factors such as contact angle and gravity level on the configuration of the gas-liquid interface.The results show that due to the presence of surface tension,the liquid climbs along the wall,the gas-liquid interface is shaped as an ellipsoidal spheroid.In the process of liquid climbing,the wettability of the liquid to the solid decreases with the increase of contact angle and gravity level.When the gravity level is less than 10^-3g and the contact angle is less than 20°,the liquid wettability area accounts for the largest proportion which is more advantageous to store the liquid propellant in orbit for a long time.