Abstract: The fill path of FDM is discontinuous, and frequent stopping of the motor can easily lead to warping and deformation. A path optimization algorithm based on contour offset and Hilbert curve fitting is proposed by combining contour offset method and Hilbert curve filling in space filling curve. In this algorithm, Hilbert curve was fitted with three B-spline curves, which reduced the motor change rate and the stopping times of the motor in the printing process, thus reducing the warpage deformation of the printed parts and improving the precision of the printed parts. The experimental results show that the average maximum warpage of the model is reduced by 60.70% and the total average warpage is reduced by 62.26%.