Constructing low-carbon and livable new cities is a new concept and trend in urban development. Considering simultaneously low-carbon emissions and climate adaptability improvements in urban planning and construction holds paramount significance. This approach plays a critical role in mitigating the effects of climate change throughout the urbanization process and enhancing the overall quality of urban life. This study selected the Chongqing Economic and Technological Development Zone as the experimental area, employing linear programming to conduct low-carbon optimization on the planned land use structure for the year 2025. Utilizing a micro-scale numerical model, the changes in wind-thermal environment were simulated within the experimental area for both January and July following the optimization of land use for low-carbon and spatial efficiency. The results indicate that the following: (1) After optimizing the land use structure for low-carbon, the experimental area reduced carbon sources such as construction land while increasing carbon sinks like forests and grasslands. The total annual land carbon emissions decreased by 19.0×104 tons, a reduction of 12.1%. (2) The combination of low-carbon optimization and spatial optimization improved the ventilation environment in the experimental area. In January and July, the average wind speeds increased by 0.8% and 1.7%, respectively, with local maximum increases of 8.0% and 11.0%. Average wind speeds increased at 61.1% and 74.4% of the locations, and an observed increase in average wind speed occurred at 12 time points and 18 time points in the daily hourly sequence, respectively. (3) After optimization, the urban heat island effect in the experimental area tended to alleviate. The average temperatures in January and July showed reductions of 1.3% and 0.7%, respectively, with maximum localized decreases of 12.9% and 5.0%. Average temperatures decreased at 61.2% and 57.7% of the locations, and all time points in the daily hourly sequence showed a decrease in average temperature. Optimizing urban land use structure for both low-carbon and spatial efficiency holds the potential to concurrently reduce carbon emissions, improve wind-thermal environment, and enhance urban climate adaptability. The results of simulation evaluations can serve as valuable references for establishing quantitative objectives in economic and social development planning, and informing key indicators for comprehensive urban planning.