The present invention relates to a flow table modifying method, a flow table modifying apparatus, and an OpenFlow network system. The flow table modifying method includes: receiving, by a switch, a modify flow entry message sent by a controller; searching, by the switch, a flow table corresponding to a flow table identifier for whether there is a flow entry matching to-be-modified target information; and in a case in which there is the flow entry matching the to-be-modified target information, changing, by the switch, a match field in the matched flow entry to a new match field. According to the flow table modifying method in an embodiment of the present invention, the switch searches the flow table corresponding to the flow table identifier for the flow entry matching the to-be-modified target information and changes the match field in the matched flow entry to the new match field.