The invention discloses a processing device of a thin-diameter thin-wall metal elbow. The thin-diameter thin-wall metal elbow comprises a base, a guide wheel I, a handle, a guide wheel II and a separation blade, wherein the base is fixedly mounted on a worktable; the guide wheel I is movably mounted on the base and can rotate around the central axis of the base; the handle is mounted on the base by a movable connecting piece and can rotate left and right around the movable connecting piece; the guide wheel II is mounted in a slot arranged in the middle of the handle; the separation blade is fixed on the base and prevents a bent tubular product from radially moving in an elbow-bending process; and molded arc grooves with the same diameter as the bent tubular product are arranged on the guide wheel I and the guide wheel II along the circumferential direction and arranged on the same horizontal line. The processing device has simple structure, convenient mounting, simple and convenient use and operation and good use effect and can process various thin-diameter thin-wall metal elbows with different strength levels; and an elbow-processing process has little influence on the performance of tubular products and has convenient and flexible operation, high efficiency and low cost.