One kind of hydraulic swell-shaping apparatus with directionally contractive shielding enclosure and its swell-shaping method are disclosed. Inside the mold for the swell-shaped workpiece to be set in, there are bottom plain cushion, pre-pressed plain cushion below the upper cover plate, pressure lever to deform the plain cushion with hole corresponding to the central hole in the lower cover plate and communicated with the hydraulic chamber. The swell-shaping process includes the following steps: first applying pressures to the upper and lower cover plates to extrude the swell-shaped workpiece; and subsequent injecting liquid through the central hole in the lower cover plate to produce hydraulic swell-shaping force to shorten the upper linear section of the workpiece and realize directional shrinkage. In addition, there is gaps between the workpiece and the plain cushion for easy loading of the workpiece into the mold.