To tackle global climate change and fulfill China's dual carbon objectives, the coordinated abatement of pollution and carbon emissions has emerged as a pivotal focus for sustainable urban development. Land use patterns and pollutant emissions are deeply connected within cities, making them a crucial lever for advancing synergistic pollution and carbon reduction. To investigate this relationship, this study constructs a synergy index (Syg) and a territorial land use compactness index (TD) using the Entropy Weighted TOPSIS method based on land raster data from 2012 to 2023, LandScan population raster data, and prefecture-level city panel data. The findings indicate that the compactness of urban land use patterns positively influences the synergistic effects of pollution and carbon emissions reduction. This conclusion remains valid after undergoing benchmark regression analysis, robustness testing, and endogeneity treatment. Regarding the operational mechanism, the compactness of urban land use patterns primarily exerts its effects through two pathways: the aggregation of innovative factors and overall industrial structure upgrading. Heterogeneity analysis further reveals that the synergistic effects of pollution and carbon emission reduction are more pronounced in eastern and western cities, non-transport hub cities, non-resource-based cities, and mature resource cities. Thus, it is recommended that differentiated land policies and green innovation clusters be established, and that a synergistic assessment system for land use, as well as pollution and carbon emission reduction, be developed to help achieve the dual carbon goals.