Abstract: A cutter with straight generatrix is difficult to fit the curved surface accurately in five-axis flank milling of non-developable ruled surfaces, in order to solve this problem, a general three-point offset strategy is proposed for initial tool positioning, geometric deviation between the cutter and the design surface is then calculated along the tool axis, the desired distribution of points on the tool axis trajectory surface is obtained according to the concept of deviation compensation, and a tool axis trajectory surface model is constructed, furthermore, the SVD algorithm is utilized to solve the model, and the optimal solution is selected aimed at the minimum sum of all machining errors in absolute form. The simulation results showed that the proposed method has obvious advantage in machining accuracy over the heuristic-algorithm-based tool path optimization methods.