For the needs of the information management of open-pit slope safety,through ana lyzing the methods for the secondary development of AutoCAD and the main idea an d key techniques of Geographic Information System (GIS),some core techniques tha tachieving GIS functions based on the secondary development of AutoCAD is studi ed and developed.Combining with the actual needs of an opencast coal mine,the GI S information system of slope safety has been developed,and its practical applic ation has been come to,meet the requirements of slope safety management in the mine.