The invention constructs a method for detecting an outcrop residual coal spontaneous combustion zone. According to the method, the geological map and remote sensing images of a research area are acquired; the geological map of the research area is vectorized, and a coal seam distribution area is extracted from the geological map; multi-period remote sensing images are preprocessed, and a decisiontree method is adopted to classify the pre-processed images, and a post-classification change detection method is adopted to extract an outcrop coal and bare land increase area; a temperature inversion algorithm is used to perform temperature inversion on the pre-processed remote sensing images, surface temperature is graded, and a surface high temperature anomaly area is extracted; and spatial superposition analysis is performed on the coal seam distribution area, the outcrop coal and bare land increase area, and the high temperature anomaly area, and the superposition area of the coal seam distribution area, the outcrop coal and bare land increase area, and the high temperature anomaly area is extracted and is adopted as an outcrop residual coal spontaneous combustion area. With the method adopted, the coal spontaneous combustion zone can be quickly and accurately extracted, and scientific basis and technical support can be provided for the ecological restoration of the coal spontaneous combustion zone and residual coal recovery.