Abstract: This application discloses a data synchronization method, where the method is applied to data synchronization between heterogeneous databases. The method includes: A terminal device records a primary key, attribute information, a version number, and a synchronization status of a data object by using a first storage format, and a cloud device records a primary key, attribute information, and a version number of a data object by using a second storage format, so that the terminal device and the cloud device implement data synchronization between the heterogeneous databases based on the storage formats and version numbers. In the technical solutions of this application, consistency in data synchronization between the heterogeneous databases may be ensured through, for example, version number management and synchronization status management.