Bearer network load balancing method, device and system based on core network flow statistics

The invention provides a bearer network load balancing method, device and system based on core network flow statistics, and the method comprises the steps: constructing a bearer network flow component diagram according to a statistical result forwarded by a core network control plane network element SMF, the statistical result is obtained by performing flow information statistics on a plurality of GTP-U tunnels by a core network user plane network element UPF and is sent to a core network control plane network element SMF; when link congestion occurs in the bearer network, acquiring to-be-scheduled traffic used for being scheduled to other non-congestion links in the current congestion link according to the bearer network traffic component diagram; and changing a flow guide rule of a bearer network access router side and changing a path through which the to-be-scheduled flow passes in the bearer network so as to schedule the to-be-scheduled flow to other non-congestion links, thereby realizing load balancing