Abstract: Optimization of land space use structure is one of the important ways to achieve low-carbon, green, and high-quality urban development. Taking Chengcheng County, Weinan City, Shaanxi Province as an example, the carbon emissions from 2011 to 2020 are estimated and analyzed, the Markov-PLUS model is used to simulate the land space use structure in 2025 under the natural development scenario, and a multi-objective planning model is constructed, taking the maximization of economic benefits, carbon emission minimization, and ecological benefit as the objective functions, and the simulated land space use structure is optimized and studied. The results show that: 1) Chengcheng County's carbon emissions show a trend of first increasing and then decreasing and then increasing, with a peak carbon emission of 848,170 tons in the past 10 years. 2) Under simulated natural conditions, the carbon emissions of Chengcheng County will reach 736,808 tons in 2025. 3) Through optimization, only considering carbon emission benefits, carbon emissions can be reduced by 10,991 tons and ecological benefits increased by 49.54 million yuan in 2025 before optimization. Carbon emission benefits, economic benefits, and ecological benefits can be considered comprehensively, carbon emissions in 2025 will only be reduced by 5,578 tons, but economic benefits and ecological benefits will increase by 90.98 million yuan and 3.46 million yuan respectively. On this basis, a low-carbon optimization strategy for land and space use structure is proposed.