The invention provides an SDN-based equivalent route Hash routing method, apparatus and system. The method comprises the following steps: a controller presetting an SDN-based equivalent route Hash algorithm configuration task sequence, wherein the task sequence comprises a flow-based Hash algorithm table; receiving a message not matching a flow table and link load information, reported by a switch, and calculating an equivalent route according to a feature code of the message; according to the feature code of the message, searching for the flow-based Hash algorithm table for performing routing, and according to the reported link load information, calculating a whole link load of the equivalent route; and according to the whole link load, determining a forwarding path from the equivalent route, and adding the forwarding path to the flow table for issuing the forwarding path to the switch. According to the invention, based on an SDN architecture, the controller can realize dynamic detection of the link load and dynamic routing, and the configuration is simple and highly efficient.