To investigate how different degree of urban polycentricity influence carbon emissions, a panel model of cities was built using data on carbon emissions and the polycentricity index of Guangdong Province’s cities between 2011 and 2020. The main conclusions are discovered: (1) The different degree of urban polycentricity in Guangdong Province exhibits a decreasing trend, urban carbon emissions are on the rise in general. Guangdong’s carbon emissions in 2020 are about 1.27 times higher than in 2011, but there are great differences in carbon emissions among cities. (2)The decrease of carbon emissions in Guangdong Province has produced impressive results, as seen by the sluggish growing trend of urban carbon emissions and the decline in carbon emission intensity (CEI). (3) The enhance in urban polycentricity is significantly associated with a rise in carbon emissions. Specifically, a 1% increase in the degree of urban polycentricity corresponds to a 0.196% increase in city-level carbon emissions. Based on the above conclusions, cities need to comprehensively consider the development stage and characteristics of cities, and take targeted policies and measures to achieve more effective carbon emission reduction (CER) targets while effectively utilizing the advantages of polycentricity.