A method of converting a routing mode of a network is provided, wherein a plurality of first routes connected a central controller to a plurality of nodes are established in the network through a spanning tree protocol and a plurality of second routes between the nodes in the network through the spanning tree protocol. The method includes enabling a firewall of each of the nodes to block the second routes; disabling a spanning tree protocol function of each of the nodes; populating a forwarding table of each of the nodes with a plurality of predetermined routing paths; and flushing the firewall of each of the nodes, wherein a plurality of third routes between the central controller and the plurality of nodes are established according to the predetermined routing paths without the spanning tree protocol, after the firewall of each of the nodes is flushed.