Abstract: The traditional casting process of pulping rotors generally adopts wooden molds. However, the manufacturing of wooden molds is complex, the molding operation process is difficult, and wooden molds are difficult to meet the size requirements. To meet the dimensional accuracy and internal quality requirements of the pulping rotor, a gravity casting scheme with 3D printed sand molds was adopted for production and development. Analog simulation was carried out through procast software. Finally, ultrasonic internal inspection and 3D scanning dimensional inspection were conducted on the castings to verify whether the quality of the rotor castings met the requirements.