This study investigates the impact mechanism of distorted land supply structures on green economic efficiency in Chinese cities, with a particular focus on the mediating and moderating role of the real estate market. Innovatively, the study constructs a comprehensive index to measure land supply structure distortion and employs spatial econometric methods for empirical analysis using panel data from 285 prefecture-level and above cities in China from 2010 to 2022. The findings reveal that: (1) distortions in land supply structure significantly hinder the improvement of urban green economic efficiency (GEE); (2) this inhibitory effect exhibits a significant spatial spillover effect; (3) housing prices play a notable mediating and moderating role in the relationship between land supply structure distortion and green economic efficiency; (4) the impact mechanisms demonstrate significant regional heterogeneity. These findings offer important policy implications for optimizing urban land supply structures and promoting green economic development.