1. A method, comprising: extracting matching information of a data packet in response to receiving the data packet; selecting a keyword from the matching information of the data packet according to flow-table match-field configuration information; searching for a match field of each-level flow table in a multi-level flow table starting from a first-level flow table in the multi-level flow table using the keyword as a search keyword, and matching the search keyword with the match field; and in response to matching a match field of a current-level flow table, executing a corresponding instruction, and in response to the current-level flow table not being a last-level flow table, executing a corresponding action.