The invention discloses a cross-domain data synchronization method and system oriented to message middleware. The cross-domain data synchronization method comprises the following steps of 1 using a source data center to capture the incremental data; 2 using the source data cent to add a subject to the incremental data and issue data change information; 3 using the destination data center to subscribe to the data change information to obtain the incremental data of the relevant topic of the local end; 4 using the destination data center to download the obtained incremental data of the related topics of the local end to the local warehouse to carry out the warehousing and loading operation. The method adopts a publish-subscribe mode to synchronize data, and solves the problem that the data required by different cloud systems are different, so as to synchronize different data, and effectively utilize network resources, storage resources and computing resources.