Abstract: Fundamental surveying and mapping is the premise and foundation of economic construction and social sustainable development, as well as long-term and arduous public welfare establishments.Surveying and mapping datum is the cornerstone of fundamental surveying and mapping work and one of the key factors to ensure its development successfully.With the continuous progress of science and technology, in order to guarantee the construction and development of cities, many cities urgently need to establish the local modern surveying and mapping datum system.Taking Zhuhai City as an example, this paper expounds the construction of modern city surveying and mapping datum system, introduces the historical situation and existing problems of urban surveying and mapping datum, and focuses on the concrete construction of modern urban surveying and mapping datum, which mainly includes technical route and method, construction content and application of achievements.

Key words: modern surveying and mapping datum, CORS, local quasi-geoid, construction, application