Research has been conducted on a wide variety of 3D printer circular fin heads. In this study, we proposed a sequence and method for a more efficient mesh study in the CFD model to calculate the Nusselt number of the circular fin head of an FDM 3D printer using the Taguchi method, sensitivity, and ANOVA. As a result, the CFD model to calculate the Nusselt number of the circular fin head of an FDM 3D printer has high sensitivity and contribution in the order of Base target mesh size, Prism layer number, and Prism layer thickness. We propose to increase work efficiency by performing mesh optimization in the order of factors with high sensitivity to level changes.