Phenylalanin ammonia-lyase (PAL) is a key and rate-limiting enzyme in the phenylpropane metabolic pathway, which plays an important role in plant growth, development and stress tolerance. In this study, we screened PAL gene family members in the whole genome of sweet potato, and the physicochemical properties, phylogeny, conserved domains, chromosomal localization and gene expression of sweet potato PAL gene family members were analyzed. The results showed that a total of 33 IbPALs genes were identified in the whole genome of sweet potato, which were unevenly distributed on chromosomes 2, 6, 9 and 15. PALs proteins have small differences in physicochemical properties and similar conserved motifs and gene structures. Multiple cis-acting elements related to abiotic and biotic stress response, phytohormone responsive and growth and development regulation are present on the promoter of IbPALs. There were collinear relationships between sweet potato IbPALs and Arabidopsis thaliana, Ipomoea trifida and Ipomoea triloba PALs genes. The transcriptome data of sweet potato showed that IbPALs gene was expressed in different tissues of sweet potato and was induced by drought stress. This study provides a reference for further understanding the function of PAL family gene in sweet potato and lays a foundation for genetic improvement of sweet potato.