Income inequality not only affects social well-being, health, and promotes carbon emissions, but also affects China's basic national policy for green development.Therefore, based on the panel data of 205 cities in China from 2010 to 2020, a panel model with partial linear functional coefficient is used to analyze and test the relationship between income inequality, carbon emissions and green development efficiency under different regional economic development levels.The research results show that: in the early stage, when the urban economic development is at a low level, income inequality has an inhibitory effect on carbon emissions and does not contribute to the efficiency of green development; Some green development efficiency has a promoting effect, but with the evolution of time, the impact of income inequality on carbon emissions and green development efficiency is gradually insignificant in areas with low and high levels of urban economic development.