A method and an apparatus for upgrading a para-virtualized network adapter kernel acceleration module are disclosed. The method includes switching a network flow of a first para-virtualized network adapter kernel acceleration module to a user mode for transmission; removing the first para-virtualized network adapter kernel acceleration module; inserting a second para-virtualized network adapter kernel acceleration module; and switching a transmission of the network flow in the user mode to a transmission by the second para-virtualized network adapter kernel acceleration module. The method and the apparatus for upgrading a para-virtualized network adapter kernel acceleration module switches between a kernel mode and a user mode for a network flow without affecting fluctuations in a network flow of a virtual machine. An upgrade of a para-virtualized network adapter kernel acceleration module is achieved, which is unnoticeable by a user, and user experience is not affected.