Sweetpotato is an important miscellaneous grain crop in China, which is threatened by a variety of diseases and insect pests in the process of cultivation and production. sweetpotato stem rot is one of the common sweetpotato diseases, which seriously affects the yield and quality of sweetpotato. However, there are few studies on the mechanism of resistance to stem rot in sweetpotato. In this study, transcriptome sequencing analysis was carried out on the samples at different stages (T1, T2, T3) of stem rot pathogen infecting Xushu 48, and 44839 (T1-VS-T2), 81436 (T1-VS-T2) and 61932 (T2-VS-T3) differentially expressed genes (DEGs) were obtained. The DEGs were mainly concentrated in Alanine, aspartate and glutamate metabolism (ko00250), Carbon fixation in photosynthetic organisms (ko00710) and Amino sugar and nucleotide sugar metabolism (ko00520) and some candidate genes related to plant pathogen infection, such as receptor-like protein kinase (RLK5, RLK7), LRR receptor-like serine/threonine-protein kinase (SERK1), bHLH137, ERF9, MYB73 and NAC053, were screened. The results of this study provide genetic resources for the research on stem rot resistance of sweetpotato and provide theoretical basis for sweetpotato resistance breeding.