To analyze the effects of drought treatments on physiological indexes and DNA methylation levels of winter Brassica Rapa, this study subjected cabbage-type oilseed rape to three treatments, namely, normal water supply, drought stress, and rehydration after drought, and analyzed the changes in the physiological indexes of oilseed rape and the DNA methylation levels of oilseed rape after the different treatments. The results showed that when cabbage-type oilseed rape was subjected to drought stress, malondialdehyde content, antioxidant enzyme activity and osmoregulatory substances increased by 167.27%、254.85%、103.24%、164.64%、49.2% and 37.79%, respectively, and osmoregulatory substances increased by 3.21μg·g-1FW, 0.048 μ g·mg-1FW, and the relative water content of leaves decreased significantly by 53.64%. The physiological indexes were significantly recovered after rewatering; the methylation level of oilseed rape showed an increasing trend after drought, and the methylation rate after rewatering was higher than that of drought and control, with the methylation rate reaching 20.56%.The GO enrichment results showed that the differentially methylated genes were enriched in the biological process, binding and molecular function.KEGG functional enrichment analysis showed that the differentially methylated genes were mainly involved in the ubiquitin mediated protein hydrolysis, cytotoxicity , ABC transporter proteins, carbon fixation in photosynthetic organisms, and other metabolism-related pathways. There was a correlation between methylation rate and physiological indicators, and combined with the GO and KEGG enrichment results, seven differentially methylated genes encoded peroxidases.