As one of the major damage modes of the aircraft fuel tank, hydrodynamic ram may cause a catastrophic destroy to the fuel tank structure. In order to analyze the hydrodynamic ram factors and effects systematically, this paper builds a validated model of the fuel tank by a full filled cube. Situations of different impact velocities, fragment masses, materials, shapes, incident angles, incident directions and various filling rates are studied. Parameters of the fragment speed decay, pressure inside the fuel tank and the deformation of the fuel tank wall are analyzed carefully. The results show that, the damage ability of the hydrodynamic ram will exacerbate with the increase of the impact velocity, mass and the filling rate. The shape of the fragment has a certain effect on the fluid pressure and the wall deformation. The incident angle and direction of the fragment will change its motion path in the fluid and then affect the hydrodynamic ram effect. Final in this paper, the least squares method is used to fit the deformation formula of the inlet and outlet wall of the simulation tank. The laws of the hydrodynamic ram of the fuel tank resulted from this paper can be used to assess the aircraft fuel system vulnerability and design reliable protection for the fuel tank.