The invention discloses a load balancing pruning method of the loop Ethernet. The method is used for solving the problems that in a traditional loop Ethernet networking pruning method, network load shairing is ununiform, tail-end slave node data transmission delay is long. The method comprises the steps that 1, a master node detects the port connecting state; 2, a slave node sends a link initialization frame; 3, the difference of the distances between the slave node of the loop Ethernet and two ports of the master node of the loop Ethernet is acquired; 4, a redundant link is pruned; 5, a user accesses a network except the loop Ethernet. According to the method, the transmission capacity that the master node blocks the port is fully utilized, and network load balancing is achieved; the node blocking position is reasonably selected, and network delay generated when data of the tail-end slave node is introduced through the loop Ethernet is reduced.