The present disclosure discloses a flow specification (FlowSpec) message processing method. In the method, a controller forwards device interface information reported by the forwarding device; selects at least one forwarding device interface to which a FlowSpec rule needs to be applied from the received forwarding device interface information; generates an application interface rule based on the at least one forwarding device interface to which the FlowSpec rule needs to be applied; and sends a FlowSpec message to the forwarding device.