To solve the problem of difficult forming of irregular bottom，the finite element numerical simulation of hydro-filling deep drawing of special-shaped bottom box was studied. The hydraulic loading path of pre-expansion and deep drawing was designed，and the forming and die-sticking properties of the parts were simulated by finite element method. In order to improve the forming quality，the process of applying active circumferential pressure was adopted. Based on the numerical simulation technology，the complex problem of applying circumferential pressure was simplified by setting local coordinate system. Three blank forms and four groups of circumferential pressure loading curves were designed. Aiming at the irregular wall thickness invariant line of box-shaped parts，the shape of deformed sheet metal is mapped on the sheet metal before deformation，and the variation law of wall thickness invariant line of each shape sheet metal under different circumferential pressure is more clearly seen. The simulation results show that the application of active radial pressure can make the wall thickness invariant line move down to the bottom of the box，reduce the thinning area and improve the uniformity of the wall thickness of the box; at the same time，it improves the clamping property and dimensional accuracy; in the process of active radial pressure deep-drawing，the circular cut-bow shape sheet metal can be formed better than the circular and square cut-edge shape sheet metal concave bottom box.