In order to resolve the transfer and processing problems of suddenly triggered information with the SCADA system， a flexible callback method is proposed based on the listener agent using the publish/subscribe message mechanism. Some problems brought about by passive processing of suddenly triggered information are described. Then a loosely coupled flexible SCADA callback framework is developed using message middleware and callback strategy while performing integration encapsulation of components. In implementing the new system， comprehensive skills of two-layers cache and message listener agent are used. Compared with the traditional polling way， engineering example test results show that the new callback technology can improve efficiency by two orders of magnitude and provide monitoring application integration with a new method for highly efficient data processing.