Overhang structure with suspended and unsupported bottom is widely used in the design of complex parts.Additive machining is seen as an effective means for machining this kind of part.A nonuniform-layer algorithm suitable for multi-axis additive manufacturing of complex part with overhang structure was proposed.The minimum ladder error of layer thickness and angle were determined according to the range of the changing direction of the multi-axis additive processing and the range of the machinable thickness.After that,point coordinates on the filling contour were obtained according to the layer thicknesses and angles on both sides.The experimental results show that compared with the traditional uniform layering algorithms,fewer filling layers with unsupported structure can be generated by this method,which greatly improves the machining efficiency and accuracy.