A data disaster recovery method performed by a disaster recovery site includes: selecting a first backup copy when taking over a service of a production site; receiving service data through a virtual machine; obtaining changed block tracking CBT) information based on a CBT technology and the received service data, where the CBT information includes incremental information generated after the disaster recovery site receives the first backup copy; and sending, by the disaster recovery site, a first message to the production site, where the first message includes the CBT information.