The study presents a new method for 5-axis machining of blisk, which consists of both roughing tunnels and finishing blades. The ruled surface is used to approximate the freeform surface of blade, and the boundary contour of the tunnel is then determined. Based on the double point offset method, the 5-axis tool paths for roughing blisk tunnel region are generated. Similarly, by linking the corresponding points on the tool center curves and the tool axis drive curves, the spiral tool paths are developed to finish milling thin-walled blades taking into account the residual stresses induced part distortion during machining. This strategy is experimentally verified.