Geological map is one of the most important carriers of geological information. It contains the condensed discoveries of geological research and understandings of geological process. In the new era of big data, the guiding theories and methods for geological mapping have been thoroughly altered. Scientists around the world have used the new methods and techniques to establish a series ofexcellent databases related to geological maps, such as OneGeology, OpenGeoscience, NGMDB, and Geological Cloud. The effective operation of these databases provides a great amount of geoscience data and convenient information services for geologists worldwide. The current paper reviews the existing databases related to geological map and their operations., This could provide experience for integrating global databases related to geological map and constructing data platforms in Deep-Time Digital Earth (DDE) Big Science Program. History of geological mapping is reviewed and the techniques and common software serving for geological mapping are introduced. In order to meet the present needs of economic society about geological information service, as well as the mission of DDE, necessary actions such as strengthening the international cooperation of geological mapping, introducing AI technique, and enhancing data sharing, are proposed.