The invention discloses a semi-sliding hydraulic bulging technology of an automobile axle housing part and a die thereof. In the invention, the semi-sliding bulging die the body of which is composed of an upper fixed module and a lower fixed module (10,10') in the middle and a left sliding module and a right sliding module (6,6') is adopted to carry out twice hydraulic bulging shaping to a reduced
pipe blank (11), wherein, after hydraulic bulging shaping at the first time, the middle of the
pipe blank is
saddle-shaped; and after being annealed, precise shaping is achieved by secondary hydraulic bulging shaping. The upper fixed module and the lower fixed module keep motionless in the process of bulging and are used for removing the parts after bulging. The left sliding module and the rightsliding module (6,6') adopt an integral structure (or are composed of parts of axial split dies) and are respectively connected with the left sliding module and the right sliding module of a three-dimensional hydraulic
machine to perform horizontal movement. The cavity of the fixed module by secondary hydraulic bulging comprises the maximum cross section of a workpiece, and the cavity of the fixed module by first hydraulic bulging is designed according to the
saddle-shaped bulging
pipe blank. The technology replaces a
casting method and a
stamping welding method, simplifies manufacturing procedures, lowers cost by 20% and improves strength and rigidity of the workpiece by 30%.