In this paper, the transcriptome sequencing results were modeled and analyzed by bioinformatics statistical methods to check the sequencing quality. RNA-seq histology was used to analyze and study gene expression levels, including differential expression of genes among samples and GO functional enrichment. The transcriptome analysis could conclude that there were 1,362 differential genes among CT vs. DT groups in the expansion stage tubers, 4,670 differential genes among DWT vs. DT groups, 332 differential genes among DWT vs. CT, and 85 overlapping differential genes among DT vs CT, DWT vs DT and DWT vs CT groups, and the transcriptome data were reliable. By Go functional enrichment analysis, DT vs. CT was mostly enriched to biological processes, and DWT vs. CT vs DWT vs DT was involved in biological processes, cellular components, and molecular functions. This paper examines the molecular mechanism of potato tuber expansion that responds to drought stress and rehydration treatment through histology and bioinformatics techniques.