The invention provides a synchronous processing method and device of process instance data. The method comprises: when a process log corresponding to the process instance data changes, acquiring change information and source information corresponding to actual change data generating the change information; syncing the change information and the corresponding source information to at least one local storage server of a workflow engine so as to synchronously process the process instance data. By using the method and device of the invention, the performance of the workflow engine can be effectively improved, and system response time can be shortened.