Low carbon concept and blue-green space system planning play a leading role in the planning and construction of the new town. By summarizing and analyzing the relevant research on low-carbon new town planning strategies and blue-green space system planning practice, this paper explores the blue-green space system planning approach of low-carbon new towns to provide a model for constructing new towns. This study explores the planning methods of a new low-carbon city from four perspectives: constructing the overall pattern of blue-green space, integrating multiple functions of landscape and city, promoting green and low-carbon with smart and ecological means, and collaboratively developing blue and green spaces. Taking Chongqing Yongchuan Science and Technology Eco City as an example, we practice the blue-green space system planning method of low-carbon New Town. Firstly,build an ecological foundation, emphasizing the penetration of blue-green space and the systematic and integrated construction method; Second, integrate the landscape and the town, including the mountain overlooking system, urban wind corridor planning, and park and greenway system planning to meet the superposition effect of multiple functions of blue-green space and low-carbon demand. Thirdly, construct a smart low-carbon city, exploring the ways of low-carbon sustainable development from the low-carbon target strategy and the construction of an urban carbon sink. Finally, sponge facilities construction is the supporting system to promote the sustainable development of blue-green space in low-carbon new towns.