The invention relates to a closed automatic rack-type exchanging worktable of a mechanical press. The closed automatic rack-type exchanging worktable comprises a foundation support, wherein the foundation support is provided with a steel rail, the steel rail is provided with one or two exchanging worktable bodies, four corners of each exchanging worktable body are respectively provided with a roller jacking apparatus, a driving apparatus is arranged between the middle portion of the exchanging worktable body and the foundation support, a guiding apparatus is arranged between two sides of the exchanging worktable body and the foundation support, a conical positioning apparatus is respectively arranged between the middle portions of two sides of each exchanging worktable body and the foundation support, a clamping apparatus is arranged between the exchanging worktable body and the foundation support, a position detection apparatus is respectively arranged in front of and behind the exchanging worktable body, the front outer wall and the rear outer wall of the exchanging worktable body are respectively provided with a steel rail cleaning apparatus for cleaning the steel rail, four automatic collision block lifting apparatuses for restricting the exchanging worktable body are arranged at intervals on the middle portion of the foundation support, four corners of the foundation support are respectively provided with an edge portion collision block apparatus, and a hydraulic pump station apparatus is arranged in the foundation support. The closed automatic rack-type exchanging worktable has the advantages of precise in guiding, accuracy in positioning, accuracy in movement distance and the like.