The invention discloses an Ethernet-based unmanned aerial vehicle formation flight control data link system and belonging to the technical field of unmanned aerial vehicle formation control. The Ethernet-based unmanned aerial vehicle formation flight control data link system includes a ground station computer, a wireless data transmission ground terminal and a wireless data transmission airborne terminal. The wireless data transmission airborne terminal is mounted on an unmanned aerial vehicle and connected to a serial port of the airborne computer of the unmanned aerial vehicle. The wirelessdata transmission ground terminal and the wireless data transmission airborne terminal form a one-to-one communication link, and the wireless data transmission ground terminal is connected to an Ethernet serial port server through a serial port level conversion module, and the Ethernet serial port server and the ground station computer are respectively connected to an Ethernet switch through a network cable to form an Ethernet local area network. According to the Ethernet-based unmanned aerial vehicle formation flight control data link system, mature hardware, such as wireless data transmission, the serial port server and the Ethernet switch, is selected for construction to provide a data chain solution with reliable work, strong performance and controllable cost for an unmanned aerial vehicle formation operation control system.