<p>Surface tension tanks are the most widely used propellant storage systems in spacecraft and primarily rely on liquid surface tension for propellant delivery and gas–liquid separation. This study focuses on the orientation and reorientation processes of propellants in a partial-controlled vane-type tank under different microgravity accelerations. The distribution of the propellant in the tank was simulated, and the results were compared with the drop tower test results. Considering the joint action of the vertical vanes and accumulator, the propellant transport performance, free liquid surface shape, and centroid distribution of the tank under different liquid filling volumes were analyzed. The results indicate that during propellant orientation, the free surface undergoes a transition from a wave-like shape to a U-shape, ultimately converging at the top end of the tank to encapsulate the gas into a pocket. Higher tank fill levels correlated with an increased propellant delivery volume and greater centroid offset. The accumulator functions to retain liquid and prevent gas ingress, thereby enabling gas–liquid separation, but does not possess active gas venting capabilities. Under extreme operational conditions, the partial-controlled system's functionality may be constrained by insufficient propellant fill/residual levels. This study provides a comprehensive investigation of propellant management processes in partial-controlled vane-type tanks and offers guidance for further optimization of vane-type propellant management devices.</p>