The multiple cropping index is an important parameter for the evaluation of cultivated land fertility and agroecological evaluation. The development of remote sensing technology makes it possible to monitor the multiple cropping index with high temporal and spatial resolution. Based on Sentinel-2 data, the Savitzky-Golay filtering method and the quadratic difference method were used to carry out a research on the extraction method of the multiple cropping index in Hainan Island, which was verified with the ground sample data in 2020. On this basis, the data set of multiple cropping index in 2016 and 2020 were extracted. According to the verification of ground survey data in 2020, the overall accuracy of land multiple cropping index in 2020 was 91.9%, and the Kappa coefficient was 0.9. This data set can be used as the basic data for the analysis of temporal and spatial changes of cultivated land resources in Hainan, and can also provide data and decision support for Hainan to implement the sustainable development strategy of tropical efficient agriculture.