The invention discloses a saving type digital thermal sublimation transfer printing paper preparation method and a pulping apparatus thereof. According to the present invention, the digital thermal sublimation transfer printing paper prepared by the method has advantages of good uniformity, high strength, good size stability, rapid drying during inkjet printing and high transfer rate; and by usingthe pulping apparatus, the automated operation can be achieved, the specified slurries can be obtained according to different conditions by arranging the circulation liquid box, and the physical properties of the digital thermal sublimation transfer printing paper are improved through the mechanical and ultrasonic pulping mode.