The invention discloses a multifunctional expansion device for an electronic product. The device comprises a central control unit, a data processing component and a data transmission component. The data processing component comprises a power component, a storage component, a projection component and a keyboard component, wherein the power component is used for providing power, the storage component is used for storing data, the projection component is used for displaying a projection, and the keyboard component is used for inputting control information. The central control unit receives a request operation from the electronic product, and outputs a control instruction to the data processing component. The data processing component is connected to the electronic product through the data transmission component, and interacts with the electronic product according to the control instruction, so as to implement function expansion. The multifunctional expansion device for the electronic product, provided by the invention, is convenient to operate, diversified in function and high in degree of integration, and effectively expands use functions of the electronic product matched with the device; and the device is convenient and practical.