The invention discloses a gateway for switching communication based on an EtherCAT (Ethernet for Control and Automation Technology) protocol and a Profibus-DP (Process Field Bus-Decentralized Periphery) protocol and a communication method thereof. The gateway comprises an EtherCAT protocol controller, an EtherCAT transceiver, an ARM (Advanced Reduced instruction set computer Machine) central controller, a public data storage chip and a Profibus-DP main station communication module, wherein the ARM central controller is bidirectionally connected with the EtherCAT protocol controller and the public data storage chip respectively; the EtherCAT protocol controller is bidirectionally connected with an EtherCAT industrial Ethernet through the EtherCAT transceiver; and the Profibus-DP main station communication module is bidirectionally connected with a Profibus through the public data storage chip. In the invention, data exchange between the EtherCAT protocol controller and the Profibus-DP main station communication module is realized through the ARM central controller, and the problem of communication interconnection switching between an EtherCAT real-time industrial Ethernet protocol and the Profibus-DP protocol is solved.