Surface conformal circuit based on the 3D printing technology has broad application prospects. However, due to the influence of machining errors in curved substrates and positioning errors in conductive circuits, it is difficult to accurately control the height of the 3D printing head for surface circuits, which affects printing accuracy. Therefore, this article takes pneumatic direct writing printing as the research object and proposes a print head height error compensation method of “ on machine measurement + line model reconstruction”. A curvature adaptive measurement point selection method is designed, which uses the inverse NURBS curve algorithm to reconstruct the measurement data and restore the real line model. By generating the print trajectory of the real circuit and replacing the original theoretical print trajectory, the print head height error is compensated. A 3D printing platform for surface conformal circuits is established independently by integrating with an on-machine measurement system. A comparative experimental plan is also designed on circuit printing before and after compensation with three shapes of circuits: straight lines, arcs, and NURBS-free curves. The results show that before compensation, in areas with high line curvature, the wire drawing phenomenon occurs at the peak of the line on the substrate, and the stacking phenomenon occurs at the valley of the line. The wire width after compensation is relatively uniform. Further measuring the resistance of each wire shows that the resistance values of each line fluctuated significantly before compensation, and the resistance values of the compensated circuit are uniform, with an average decrease of about 65. 99% compared to before compensation, and a maximum resistance decrease of 85. 75% .