Hydraulic device with automatic positioning function

The hydraulic device with the automatic positioning function comprises a main machine table, a controller is installed on the front face of the main machine table, machine cases are installed on table bodies on the two sides of the main machine table in a penetrating mode, a positioning table is arranged in the main machine table and penetrates through the top end of the main machine table, and four pressurizing pieces and four positioning pieces are installed at the top end of the positioning table. A fixing table is arranged in the middle of the upper section and the lower section penetrating through the positioning table, a stand column is installed at the top end of the fixing table, a top sealing table is installed at the top end of the stand column, and four hydraulic cylinders are installed at the positions, close to the edges, of the upper end and the lower end of the top sealing table. A plurality of balls are arranged at the positions, close to the bottom end and located in the main machine table, o