Abstract: Many parts with closed cavity structure are widely used in many fields. This kind of structure has large incline angle, the molten pool will collapse and even the forming is unable to continue, when the way of horizontal slices is adopted. Especially, there is interference between parts deposited and the laser beam by the method of variable angle normal direction slices without adjacent layers. Based on hollow laser beam inside powder feeding technology, the closed hemisphere shell parts was researched. The closed hemisphere shell parts were divided into two parts including normal direction slices area and oblique orientation slices area. Normal direction slices method was used to eliminate staircase effect when depositing normal direction area and the oblique orientation dislocation slices method was adopted to avoid interference between parts deposited and the laser beam. The offset model of oblique orientation oblique orientation was established and the feasibility was verified by inclined wall depositing experiment. The cladding forming of the closed hemisphere shell was finished. Results show that the surface of the formed parts is smooth, the size error is within 5%, the thickness is stable around 2.7 mm, the microstructure of two forming area is compact, the distribution of hardness and tensile strength are stable.