In this paper, we studied the plantlets of potato variety ‘Qingshu 9’ under simulated drought stress to explore the molecular mechanism of potato stem under drought stress, respectively, and the stems of plantlets were used for transcriptome sequencing. The results showed that: (1) the contents of proline, soluble sugar and soluble protein were increased with the increasing concentration of PEG6000. Under three different droughtstressed conditions, there were more downregulated candidate genes than upregulated candidate genes with a total of 657 differential expression genes (DEGs) in potato stem. (2) GO enrichment analysis showed that the DEGs in potato stems mainly focused on oxidationreduction process, response to hormone, oxidoreductase activity, glycosylhydrolase activity. KEGG pathway enrichment analysis showed that the DEGs in potato stems mainly involved in plant hormone signal transduction, phenylpropanoid biosynthesis, zeatin biosynthesis, phenylalanine metabolism, starch and sucrose metabolism, biosynthesis of secondary metabolites. (3) Realtime fluorescence quantitative PCR (qPCR) was used to verify the expressions of six DEGs under different droughtstress conditions. The results were basically consistent with the transcriptome profile that proved the reliability of our RNAseq data. Our research provided the valuable information for understanding the drought resistance mechanism of potato, and enriching the genetic resources of drought resistant potato breeding.