Abstract: With the rapid development of FDM 3D printing technology, industries have raised increasingly stringent requirements for printing efficiency and forming accuracy. Aiming at the insufficient forming precision of FDM 3D printers, this paper conducts a consistency analysis on error factors affecting machining accuracy of the printer and verifies the feasibility of error consistency analysis and optimized design via modeling. The research findings provide a novel theoretical design approach for precision improvement of FDM 3D printers and offer engineering references for enhancing dimensional accuracy, surface quality of printed parts and overall machining performance of the equipment.