To explore the impact of green technological progress and its bias on the synergy of pollution reduction and carbon emission reduction, this study utilizes panel data of 251prefecture-level cities in China between 2007 and 2021, it employs the EBM model with undesirable outputs and the Malmquist-Luenberger index to measure green technological progress and separate biased technological progress at the city level. Then, after employing the coupling synergy degree model for evaluating the synergy degree of carbon emissions and air pollutants, this paper empirically analyzes the specific influences of green technological progress and its bias on air pollution and carbon emission reduction, as well as the mechanism through which it exerts its influences. According to the research findings: Green technological progress and capital-augmenting labor-saving technological progress can significantly promote the synergy between pollution reduction and carbon reduction, the average effect is 0.023 and 0.005. The promoting effect remains robust after a series of robustness checks and treatments for endogeneity. Green technological progress can promote the synergy between pollution reduction and carbon reduction by increasing the accumulation of human capital, with a mediating effect accounting for 8.7%. Government environmental regulation plays a positive moderating role between human capital and the pollution-carbon reduction synergy, with a moderated mediation index of 0.008. However, capital-augmenting labor-saving technological progress, while improving the synergy, is detrimental to the enhancement of urban human capital. According to the results of the heterogeneity analysis, green technological progress has a stronger promoting effect on the synergy in small and medium-sized cities and in the east of the Hu Line, while in super large cities, very large cities, and large cities, it hampers the synergy between pollution reduction and carbon reduction. Meanwhile, the negative effects are more pronounced in large cities. Capital-augmenting labor-saving technological progress has a stronger promoting effect on the synergy in super large cities, very large cities, and in the west of the Hu Line.