The invention discloses a novel efficient board single-side putty applying machine which comprises a rack, a transmission mechanism, a coating and scraping mechanism and a power mechanism. The rack comprises channel steel, angle steel, a steel plate and square steel, the transmission mechanism comprises a drive roller, a driven roller, a pressure roller, carrier rollers, a tensioning roller and a conveyer belt, the coating and scraping mechanism comprises a putty squeezing roller, a putty coating roller, a support, a double-edged knife and an oblique scraper, and the power mechanism comprises a motor, a speed reducer, an electric control cabinet and chain wheels; sliding bearing seats are arranged on the shaft ends of the drive roller and the driven roller, a screw is arranged on one side of the center of each bearing seat, a nut is arranged on the head of each screw, and the bearing seats are fixedly connected to the rack through the screws and the nuts; the double-edged knife, the putty coating roller and the conveyer belt form a triangle area together, and the rear side of the double-edged knife is provided with the oblique scraper. According to the novel efficient board single-side putty applying machine, automation of applying putty on boards is achieved, the time and the energy are saved, the efficiency is high, and the quality is high.