This article is a quantitative study of the urban expansion of Beijing in the past two decades and its impact on the city’s heat island effect. The overall idea of this paper is a ‘basic fact description to phenomenon and law reveal-basic cause analysis-mechanism analysis-model simulation’. In this paper, the effects of urbanisation on warming in Beijing are deduced by nonlinear fitting method. Based on Google Earth Engine remote sensing image data within Beijing Inner Sixth Ring Road and using ArcGIS to retrieve Beijing’s surface temperature, the heat island effect intensity index is calculated. This paper quantitatively analyses the temporal and spatial distribution characteristics and development trends of Beijing’s urban heat island effect, combined with land use cover change (LUCC), Land Surface Temperature (LST), Normalised difference Vegetation Index (NDVI), Normalised difference Building Index (NDBI), which can explore the impact of surface vegetation distribution and building density on the urban heat island effect.