[Objective] The transfer characteristics of land use types and its impact on the thermal environment in the process of urbanization were studied, in order to provide scientific basis for optimizing the land use pattern and regional development and management in the context of low carbon.[Methods] Take Haiyan County, Zhejiang Province as a case study area, based on the four Landsat satellite images, the county-level land use types were interpreted and surface temperatures were derived. The spatial and temporal distribution of urban heat islands and the impact of land use type transfer on the thermal environment were analyzed by the land use transfer matrix and the contribution index of thermal effect.[Results] From 2007 to 2017, the built-up area in the central urban area of Haiyan County expanded significantly, the pattern of land use also changed significantly, and the dynamic degree of land use reached to 42.3%. The urban land area increased significantly, with a transfer rate of 44.1%, mainly transferred from vegetation and roads. The vegetation coverage area decreased significantly, and the transfer rate was 51.2%, mainly transferred into urban land and roads. The distribution of urban heat island was gradually dispersed from the concentrated island to the edge of urban area. With the increase of urban area, its thermal contribution increased from 59.6% in 2007 to 87.5% in 2017.[Conclusion] Urban land use is a decisive factor affecting the thermal environment of Haiyan County. In the process of urbanization, reasonable and effective planning and control of the expansion of built-up areas is important measures to slow down the heat island effect.