A method and an apparatus for processing a data packet based on parallel protocol stack instances, where lower-layer protocol processing is performed, using a first protocol stack instance. An associated second protocol stack instance is determined using a target socket after the target socket that is needed to perform upper-layer protocol processing on the data packet is determined, and the upper-layer protocol processing is performed, using the target socket and the second protocol stack instance. The second protocol stack instance that performs the upper-layer protocol processing is determined using the target socket, and hence, a technical problem that protocol processing cannot be performed on a data packet because a protocol stack instance specified by an application (APP) conflicts with a protocol stack instance specified by a network adapter is resolved.