Vegetation coverage is an indicator that reflects the basic situation of vegetation. Obtaining digital images of the surface and further extracting vegetation coverage has become a measurement method with the greatest potential for obtaining coverage. In order to use digital images to quickly extract potato coverage, the vegetation coverage extraction algorithm (VCEA) was firstly used to obtain the measured potato coverage from ground digital images, and then the EXG index method and maximum likelihood supervised classification were used to digitally measure the drone image processing to obtain potato coverage in each study area. In addition, a new algorithm that used color conversion space HSI (H-A method) was proposed to quickly extract potato coverage from digital images. Finally, the accuracy of three different methods was used to evaluate and compare the calculation results. The results showed that the accuracy of vegetation coverage estimated by H-A method was the highest, all of which were above 0.91, and the fitting degree of fitting function reached 0.97;the second was supervision classification method, the lowest precision was 0.75, the fitting degree was 0.82, and the worst was EXG index method, the lowest precision was 0.74, the fitting degree was 0.74. Therefore, the accuracy and reliability of H-A method were high.