In this study, the planning technology exploration of “three plans in one” is treated as the research object, and on the basis of the summary of domestic and foreign research results and practical experience, this paper combines the "three-in-one" pilot work in the cities including Guangzhou, Heyuan and Yunfu, etc., the objective is to eliminate the contradictions and differences in the national economic and social development planning, urban and rural planning amd land use planning. Based on multi-source spatial information fusion technology, and combined with the current planning system reality and modern urban space governance theory, the “three plans in one” approach characterized by "one information platform, one set of development objectives, one map, one set of project library and one set of implementation and coordination mechanism" is constructed to achieve "one space for one city, and one plan for one space".  The research won the third prize of Science and Technology Progress Award of Guangdong Provincial Civil Construction Society in 2015.