Abstract: Aiming at the bottleneck of difficult-to-cut machining technology brought about by the hard and brittle nature of ceramic materials, a process for 3D printing precursor ceramic materials-thermo-setting modeling (TSM) was developed. Based on this process, a 3D printer screw extruder for precursor ceramic materials was designed and optimized. First, the ratio of precursor ceramic materials was determined and the material properties were tested. According to this, a thermosetting deposition molding process was proposed. Second, the precursor ceramic material screw extrusion device was designed and the preliminary printing experiment was carried out. Third, through ANSYS Fluent simulation, the internal flow field of the screw extrusion device during the printing process was analyzed. It will provide the basis for optimized design. Finally, the screw extrusion device was optimized. To get higher printing accuracy, the original 0.6 mm nozzle diameter is reduced to 0.5 mm. Through the simulation analysis, the screw rotation speed increases from 40 r/min to 60 r/min, and the gap between the outer diameter of the screw and the inner wall of the barrel is reduced from 0.50 mm to 0.25 mm to improve the printing efficiency by 49.1% and verified by printing experiments. Results show that the screw extrusion device designed in this paper can meet the requirements of 3D printing accuracy and efficiency and can print complex ceramic parts with complex shapes. It provides a way and method for shaping ceramic parts.