Abstract: The traditional casting process for pulp rotors generally uses wooden molds, but the complex structure of pulp rotors increases the difficulty of making wooden molds. The minimum production cycle for wooden molds is 20 days, while 3D printed sand molds can be directly imported into digital molds for printing, with a production cycle of only 1 day; The production cost of wooden molds can reach tens of thousands of yuan, while 3D printing sand molds eliminate the cost of mold making. 3D printing sand molds do not need to consider the starting angle of the mold, and have high efficiency in molding and box production, especially suitable for complex structured pulp rotor castings. Therefore, this article adopts 3D printed sand mold gravity casting for the production of pulp rotor,and simulates it through Procast software to optimize parameters such as riser size and improve the process yield of pulp rotor castings. Finally, chemical composition and mechanical properties, ultrasonic internal inspection, and 3D scanning dimension inspection were conducted on the optimized pulp rotor castings. The results showed that the quality of the pulp rotor castings produced by 3D printed sand molds met the requirements.