In order to accurately obtain the distribution information of crops in areas with more clouds and rains, this paper takes Heishi Township and Emu Town in the northwest of Dunhua City as the research area, and uses GF-1 WFV and Sentinel-1 as the data source, extracts the range of cultivated land through WFV data,uses J-M distance separability to judge the optimal classification time-phase combination of Sentinel-1 image. According to the selection of Sentinel-1 data, the distribution information of the main crops in the study area is extracted by the nearest neighbor classifier multiple cycles. The results show that the classification results produced by multiple cycles are better than the single cycle results. The number of cycles reaches 5 times and the results tend to be stable, and the overall classification accuracy is 84.23%. It can be seen that it is feasible to use Sentinel-1 data to classify crops in Dunhua City.The multi-cycle nearest neighbor algorithm is beneficial to obtain more accurate crop distribution information.