The invention discloses a hot-filament chemical vapor deposition batch preparation method of a complicated-shape diamond coated cutting tool in the technical field of mechanical machining, comprising the steps of: placing a sandwich type foundation on which the cutting tool is arranged on a CVD (Chemical Vapor Deposition) equipment water-cooling worktable through inserting a cutting tool holder of a pretreated complicated-shape hard alloy cutting tool; adopting two lines of hot filaments, wherein the upper line of hot filaments is as high as the nose of the hard alloy cutting tool and the lower line of hot filaments is as high as the bottom of the cutting edge of the cutting tool; and filling hydrogen and acetone and depositing a diamond coating on the surface of the complicated-shape hard alloy cutting tool. According to the the invention, the surface temperature of an underlayer at the cutting edge can be effectively reduced, the rate of the deposition is not decreased and the quality of the diamond coating is improved.