The invention discloses a processing method for a turbine of an ORC expander power generation device: (1), performing rough turning on the end face of a blank to obtain a part and performing flaw detection on the part; (2), rough turning the part, and removing a large margin of the part; (3) ), check the mechanical properties of the part material; (4), semi-finish the end face and outer meridian surface of the part, and pass through the inner hole in the part at one time (5), and draw the milling datum line of the flow channel on both sides; (6), milling flow Road; (7), semi-finished car outer meridian surface and inner hole, adjust the beating requirements of outer meridian surface and inner hole; (8), coarse dynamic balance test; (9), overspeed test; (10), finish car parts End face, outer meridian face and inner hole; (11), draw keyway and end face hole position reference line on the part; (12), process keyway; (13), drill end face hole; (14), dynamic balance test; (15) ), flaw detection of parts; (16), pliers, deburring. The invention has the advantages of small error and high precision.