The invention discloses a main machine of a mechanical high-speed fine blanking press machine for a servo motor-driven primary motion. The main machine comprises a frame, a primary punching device and a driving device, wherein the driving device comprises a direct-drive servo motor and a planetary reducer; the primary punching device comprises a toggle link mechanism, a slide block, a lower worktable and an upper worktable which are successively arranged from bottom to top; the toggle link mechanism is hinged to the bottom of the slide block; the slide block can be movably mounted on the inner side of the frame up and down; the lower worktable is fixedly mounted above the slide block, and the upper worktable is mounted on the inner side of the frame and is located above the worktable; the direct-drive servo motor together with the planetary reducer drives the toggle link mechanism to drive the slide block to reciprocate up and down so as to provide a primary blanking deformation force and a primary blanking movement. The primary blanking deformation movement comprises high-speed blanking mode and an inching mode. According to the main machine disclosed by the invention, optimized movement characteristic curve, speed characteristic curve and other movement mechanical properties of the slide block can be obtained.