Abstract: The adaptive filling algorithm for rotary frame structures is proposed, based on the introduction of cylindrical coordinate welding equipment. The number of invalid judgments was reduced by three priority screening. An error model for stacking deposits is established and the thickness of the forming layer is calculated combined with the error model and sectional curvature. The NURBS curve is used as the basis function for the least square fitting of the hierarchical profile. The genetic algorithm is used to find the best fitting weights and optimize the fitting results. The experimental results show that the welding torch operates smoothly and the cantilever shimmy is smaller; The special rotation structure of cylindrical coordinate is adopted to fill the arc, so that the forming time waiting and the over accumulation caused by the broken line contour are avoided. Finally, the stability and feasibility of layered software are verified by a practical case.