The computational and experimental studies have been performed to investigate the hydrodynamic process of liquid propellant reorientation for the launch vehicle series fuel tanks in microgravity environment. The VOF method was used to simulate the free surface flow of gas-liquid. The process of the liquid propellant reorientation started from initially curved interface at low Bond number. The propellant reorientation flow procedure at high Bond number was obtained from numerical simulation and scale model experiment in drop tower. The numerical results agreed well with the experiments. The results can be used to adjust the engineering reorientation parameters.