The present invention provides a packaging shell and a power module having the same. The packaging shell mainly comprises an accommodating recess for receiving a substrate disposed with a plurality of electronic devices/components, so as to make the substrate be further assembled with a heat sink through the support of the packaging shell. Most importantly, in the present invention, the accommodating recess has a stepped surface for contacting with the substrate, and the stepped surface is a curve surface having a flatness difference. By such design, the compressional force generated when assembling the packaging shell, the heat sink and the system circuit board can be uniformly transmitted to substrate via the curve surface structure; such that the compressional force is avoid from being concentrated to a certain point on the substrate, and then the substrate is protected from being ruptured due to the action of the concentrated compressional force.