The embodiments disclose a packet control method, a switch, and a controller. The method includes receiving, by a switch, a packet, and processing the packet according to a pipeline, where an original packet is stored in a buffer, and a buffer location of the original packet is identified by using a buffer identifier. The method also includes when the packet fails to match a flow table, sending, by the switch, a first packet message to a controller, where the first packet message carries the buffer identifier, all or partial content of the packet; receiving, a second packet message sent by the controller, where the second packet message carries the buffer identifier and a packet processing instruction, and the packet processing instruction includes indication information of a specified flow table. Additionally, the method includes reprocessing, the packet according to the packet processing instruction and starting at the specified flow table.