A pre-folded medical self sealing pouch closes accurately with a concavepressing mark formed between two counter rotating cams. A top cam has anannularprotrusion mating with an annular recess on the lower cam. The medical selfsealingpouch comprises a bag body which is formed by heat-sealing a first surfacelayer anda second surface layer, wherein a seal lip on the second surface layer extendsoutwards from the bag mouth of the bag body； and at least one adhesive layerisprovided on the surface of the seal lip directing at the first surface layer,separated with themouth of the bag body. The folding pressing mark is close to one edge of theadhesiveclose to the mouth of the bag body so that the adhesive is pasted to the firstandsecond surface layers after the seal lip is folded along the folding pressingmark.
