Using "radial rectangle mapping" to convert radially distributed radar data into grid point data; complete the mapping of window mapping and isosceles triangle detection template at the same time, so as to obtain the description of the convergence intensity and position of the convergence point on the basis of quickly locating the convergence point The parameter vector of. Analyze the characteristics of urban thermal environment changes in East China. The results show that the urban heat island area in East China expanded from 2012 to 2022, especially in Changle District, Fuqing City, and Shangjie Town in Minhou County. The characteristics of urban thermal environment changes in East China were analyzed. The results show that the urban heat island area in East China expanded from 2012 to 2022, especially in Changle District, Fuqing City, and Shangjie Town in Minhou County.