Embodiments of the present invention disclose a data migration method for memory modules in a server and a server. By establishing a mirror relationship between agent apparatuses of two memory modules, a processor in the present invention instructs the agent apparatuses to perform data migration between the two memory modules, to complete migration of data from one memory module to the other memory module. The entire data migration process requires no participation of an operating system, and consumes a short period of time, thereby implementing convenient data migration for memory modules in a server.