The invention belongs to the technical field of machining and relates to a method for machining a rotor spindle of a high pressure turbine. Finish turning process is performed by using a rubber belt to wind parts, so that deformation of thin-walled workpieces is avoided. Spot facing machining tests cutting parameters, tool wear is controlled, and tool changing points are determined. Intensity check is performed on simulation test sheets through shot blasting so as to guarantee shot blasting intensity of the parts. The parts are subjected to static balance detection and superposition projection detection after processing. The method for machining the rotor spindle of the high pressure turbine includes the following steps of rear end positioning, front end half finish turning, front end positioning, rear end half finish turning, rear end positioning, front end finish turning, front end positioning, rear end finish turning, end face hole and fan-shaped groove machining, shot blasting, spigot finish turning, static balance detection, and superposition projection detection.