Interface expansion device

The utility model discloses an interface expansion device, which is used for expanding interfaces of main boards. The interface expansion device comprises a controller and at least two expansion interfaces, wherein the controller is electrically connected with an interface of a main board, the expansion interfaces are electrically connected with the controller, and the controller controls data transmission of the expansion interfaces. Through disposing the controller and the at least two expansion interfaces on an expansion board, the main board is not required to be equipped with a pluralityof interfaces, thereby realizing the purpose of decreasing the area of the main board and reducing the cost thereof. Simultaneously, the expansion board is electrically connected with the interfaces on the main board, thereby bringing convenience for users to expand the interfaces of the main board.