Abstract: In order to acknowledge the county-level wheat planting area more accurately, the author took Pinghu City of Zhejiang Province as an example, used the image data of GF- 1 and RapidEye satellite, extracted the approximate wheat planting area by supervised classification method, stratified sampling in wheat planting area range, estimated the wheat planting area in Pinghu City in 2015 which was 141.73 km2 with 95% confidence interval 95% estimation accuracy. The results were comparatively consistent with the actual wheat planting area in Pinghu City, indicating it was feasible to use supervised classification method combining stratified sampling to estimate the county-level grain planting area. This method was suitable for the regular operation of county-level grain planting area in Zhejiang Province.