The invention discloses an airtight three-dimensional system-level package. The package provided by the invention can achieve the packaging of more chips in the smallest space. Through the ingenious packaging structural body design and the application of electrical connection points, six ceramic substrates of a package body can be used for installing chips, and the electrical connection points areconnected mutually, thereby enabling the substrates to be electrically connected. The airtight three-dimensional system-level package is formed through an airtight welding ring, and all elements arelocated in the package body and are protected effectively. Through the selection of different ceramic substrate materials, the heat dissipation problem of a big-power device is solved.