The invention discloses a hot isostatic pressing forming method for a homogeneous sheath. According to the method, a hot isostatic pressing (HIP)/selective laser melting (SLM) 3D printing compound technology is adopted. The problems that the production period is long, the manufacturing cost is high, the sheath removing process is complicated, the connection interface has diffusion reaction to pollute a manufactured piece and the like when a heterogeneous sheath with a complicated shape is formed by the traditional method is solved by the homogeneous sheath which is formed by the SLM adopted by the invention. Meanwhile, the inner side surface (the surface where the homogeneous sheath is in contact with powder in hot isostatic pressing) of the homogeneous sheath is designed into a gradient porous gradual change structure, so that the tissue at the connection interface has a gradient change structure after hot isostatic pressing, so that the defect that the tissue and performance of an interface between the homogeneous sheath formed by SLM and an HIP compact body are choppy is overcome, and the manufacture piece with excellent mechanical performance is finally formed.