Climate change affects lemon growth, yield and quality. In order to study the change of climate suitability distribution of Citrus Lemon in Yunnan under the background of future climate change, the daily meteorological data of 125 national meteorological stations in Yunnan from 1981 to 2018 are used. Based on the climate suitability regionalization of lemon in Yunnan Province, the climate suitability regionalization of lemon in 2021-2030, 2031-2040 and 2041-2050 are studied using RCP2.6, RCP4.5 and RCP8.5 climate scenarios. By the middle of the 21st century, lemon’s most suitable planting area under RCP2.6, RCP4.5 and RCP8.5 increased by about 30%, 50% and 9%, respectively. However, because of the limitation of precipitation factor, the moderate suitable area will decrease from 2041 to 2050, and the total suitable area (high suitable area + medium suitable area) will be stable, providing a broad space for lemon planting development in Yunnan.