The invention provides an integrated double-flange supporting device for a rotating ultrasonic transducer. According to the integrated double-flange supporting device for the rotating ultrasonic transducer, a double-flange structure is adopted, the problem of tail swing during high-speed rotating due to the fact that the ultrasonic transducer is long is solved, and limit rotating speed and machining precision of an ultrasonic main shaft are improved. Conical surfaces are made of outer cylindrical surfaces of two flanges on the ultrasonic transducer, conicity of the two conical surfaces is same, and the two conical surfaces are coaxial; an inner conical surface and an outer conical surface are made on the cavity inner wall of the main shaft, one-time clamping and machining can be achieved, coaxiality of the two conical surface is improved, and centering precision of the ultrasonic transducer is improved accordingly.