An expansion module (100, 200, 300) for providing expansion functions for a mobile electronic device, comprising: a cloud device (110, 210, 310) comprising a first expansion bus interface (112, 212, 312) and a first network interface (114, 214, 314), wherein the cloud device (110, 210, 310) provides network function through the first network interface (114, 214, 314), and provides at least one first peripheral device (132_1, 132_2, 132_n, 232_1, 232_2, 232_3, 232_4) to the mobile electronic device for use through the first expansion bus interface (112, 212, 312) or the first network interface (114, 214, 314); and a first expansion device (120, 220, 320), comprising at least one second peripheral device (128, 228, 328), a second expansion bus interface (122, 222, 322), a third expansion bus interface (124, 224, 324) and a second network interface (126, 226, 326), the second expansion bus interface (122, 222, 322) being coupled to the second peripheral device (128, 228, 328), the third expansion bus interface (124, 224, 324) and the second network interface (126, 226, 326), and being used for coupling to the mobile electronic device, the third expansion bus interface (124, 224, 324) being used for coupling to the first expansion bus interface (112, 212, 312) and the first network interface (114, 214, 314) of the cloud device (110, 210, 310), wherein the first expansion device (120, 220, 320) provides the network function through the second network interface (126, 226, 326), and provides the second peripheral device (128, 228, 328) to the mobile electronic device for use through the second expansion bus interface (122, 222, 322); the mobile electronic device detects the first network interface (114, 214, 314) and the second network interface (126, 226, 326) and instructs the expansion module (100, 200, 300) to provide the network function to the mobile electronic device for use through the first network interface (114, 214, 314) or the second network interface (126, 226, 326) wherein the mobile electronic device uses the network function provided by the first network interface (114, 214, 314) of the cloud device (110, 210, 310) when the first network interface (114, 214, 314) and the second network interface (126, 226, 326) are simultaneously detected by the mobile electronic device. a cloud device (110, 210, 310) comprising a first expansion bus interface (112, 212, 312) and a first network interface (114, 214, 314), wherein the cloud device (110, 210, 310) provides network function through the first network interface (114, 214, 314), and provides at least one first peripheral device (132_1, 132_2, 132_n, 232_1, 232_2, 232_3, 232_4) to the mobile electronic device for use through the first expansion bus interface (112, 212, 312) or the first network interface (114, 214, 314); and a first expansion device (120, 220, 320), comprising at least one second peripheral device (128, 228, 328), a second expansion bus interface (122, 222, 322), a third expansion bus interface (124, 224, 324) and a second network interface (126, 226, 326), the second expansion bus interface (122, 222, 322) being coupled to the second peripheral device (128, 228, 328), the third expansion bus interface (124, 224, 324) and the second network interface (126, 226, 326), and being used for coupling to the mobile electronic device, the third expansion bus interface (124, 224, 324) being used for coupling to the first expansion bus interface (112, 212, 312) and the first network interface (114, 214, 314) of the cloud device (110, 210, 310), wherein the first expansion device (120, 220, 320) provides the network function through the second network interface (126, 226, 326), and provides the second peripheral device (128, 228, 328) to the mobile electronic device for use through the second expansion bus interface (122, 222, 322); the mobile electronic device detects the first network interface (114, 214, 314) and the second network interface (126, 226, 326) and instructs the expansion module (100, 200, 300) to provide the network function to the mobile electronic device for use through the first network interface (114, 214, 314) or the second network interface (126, 226, 326) wherein the mobile electronic device uses the network function provided by the first network interface (114, 214, 314) of the cloud device (110, 210, 310) when the first network interface (114, 214, 314) and the second network interface (126, 226, 326) are simultaneously detected by the mobile electronic device.