Provided are a switch and a service request packet processing method, belonging to the technical field of networking. The method comprises: receiving an initial service request packet; determining a matching flow table entry carrying a command instructing reversal of a preset portion in a packet header field and execution of a preset action on the initial service request packet; reversing the preset portion in the packet header field of the initial service request packet according to the matching flow table entry, executing the preset action on the initial service request packet according to the matching flow table entry, and obtaining a service response packet; sending the service response packet. In the present invention, after the matching flow table entry matching the initial service request packet has been determined, the preset portion in the packet header field is reversed and the preset action is performed on the initial service request packet according to the matching flow table entry, and the service response packet is obtained, so that when the service response packet is acquired, implementation is local to a switch, not only increasing service processing efficiency between a controller and the switch, but also reducing interaction costs between the controller and the switch.