The invention discloses a device and a method for differential centrifugal spinning by using air flow to assist a melt, and belongs to the field of spinning forming. The device comprises a melt metering pump, a material hopper, a continuous material supply device, an air pipe, a receiving device, an electromagnetic heating bracket, a motor, an electromagnetic heating device, a spinning tank body, a spray head bracket, a slide rail, a shaft, a centrifugal differential disc, a spray head, a spray head heating coil, a thermocouple, an infrared temperature measuring instrument, an air pipe bracket and the like, wherein the melt enters the centrifugal differential disc through the eccentric spray head to obtain the initial linear speed, is equalized by a plurality of grooves which are formed in the disc center, enters a comb tooth-shaped structure of the conical surface of the disc edge, is thinned, differentiated and fined under the actions of centrifugal force, high-speed air flow and attaching force of the melt on the conical surface, and is thrown out at high speed, so as to finally form superfine fibers. The device and the method have the advantages that in the fiber preparation process, the efficiency is high, and the green and pollution-free effects are realized; the prepared fiber has higher net surface density and degree of orientation, and the property is excellent; the device is simple, the processing is easy, and the device is suitable for preparing the superfine fibers in a batch way.