The invention discloses an ultra-thin battery case manufacturing process, which is characterized by comprising the following steps: (1) processing raw materials: cutting rolled plastic into sheets by a cutting machine; (2) thermal forming: processing the rolled plastic through thermal forming; (3) punching an outer frame: cutting and removing outer frame waste materials on four sides of a thermalformed product; (4) boring an inner hole: boring the inner hole in the middle of the thermal formed product and cutting part of two side edges of the plastic to be convenient to splice and combine the two side edges of the plastic; and (5) sticking a double faced adhesive tape: sticking the double faced adhesive tape on the surface of the thermal formed product. The invention solves the problems in the prior art that during the forming process, the limitation of the battery case manufacturing process to the thickness of material is very great, the plastic is very easy to pull open and damage during the drawing process, and the production costs of enterprises are increased. The invention provides the ultra-thin battery case manufacturing process, the thickness of the wall of the drawn plastic is small, the drawing height is greater, and the plastic is not pulled open and damaged.