Firewall real-time data traffic monitoring method, device, system and medium

The invention provides a firewall real-time data traffic monitoring method, device and system and a medium. According to the method, a first transmission characteristic parameter of first to-be-monitored data passing through a first layer of firewall on a first communication link and a second transmission characteristic parameter of the first to-be-monitored data passing through a second layer of firewall are obtained, and the second transmission characteristic parameter comprises first actual flow information of the first to-be-monitored data; and determining a first data monitoring state of the first to-be-monitored data according to the first predicted flow information, the first actual flow information and the first authorization information, and determining a third communication link according to the first data monitoring state and a preset communication link selection model, thereby transmitting the first to-be-monitored data to the target terminal device. Therefore, the first data monitoring state is d