The present application discloses a long-distance transmission method for an Ethernet switch including a network switching module, an MCU module and a dial code module. The MCU module is connected to the network switching module and the dial code module. The dial code module is configured for providing two configuration inputs for a normal mode and a long-distance mode for user equipment. The MCU module is configured for monitoring a configuration input state of the dial code module in real time. When detecting that the dial code module is in the configuration input for the normal mode, the MCU module configures a network port of the network switching module to be in a self-negotiation mode. When detecting that the dial code module is in the configuration input state for the long-distance mode, the MCU module configures the network port of the network switching module to be in a 10 Mbps full-duplex mode and controls an amplitude of an output voltage of a network signal of the network switching module to increase. The network switching module is configured for negotiating a network link bandwidth of 10 Mbps and a full duplex mode between the network switching module and the user equipment for long-distance data transmission according to a configuration made by the MCU module when the dial code module is in the long-distance mode. The embodiments of the present application are applied to long-distance data transmission.