A transmission line corridor channel surface feature automatic extraction method comprises the following steps: S1, setting a transmission corridor channel buffer area; S2, preprocessing a GF-1 satellite multispectral image; S3, performing sample extraction based on the GF-1 satellite image; S4, classifying the preprocessed GF-1 satellite multispectral image based on an object-oriented hierarchical classification method to get classification result data of a study area; and S5, performing fast extraction and change detection on surface features in the corridor buffer area based on multi-period classification results. According to the invention, through automatic processing of multispectral data of the domestic GF-1 satellite, the surface features of a transmission corridor channel, such as vegetations, farmlands, waters, building areas, bare lands and grasslands can be quickly segmented and extracted, fire burning marks, farmland farming change and surface vegetation coverage change can be interpreted quickly, and the efficiency and accuracy of transmission corridor channel change detection are improved significantly.