Plant height is a key agronomic trait in soybeans, directly influencing yield potential and agronomic performance. In this study, the tall-stem cultivar Heinong 63 and the dwarf-stem cultivar Longken 3077, along with their F₂ populations, were used as experimental materials. A preliminary mapping using the bulk segregant analysis sequencing (BSA-Seq) approach enabled us to locate the target locus within a 1.8 Mb interval, which was subsequently narrowed to a 48.3 kb region using simple sequence repeat (SSR) and insertion and deletion (InDel) markers. The interval was designated as PH19-31 and contained nine annotated genes. One InDel marker, PL7, was developed within this fine-mapped region. Based on an expression analysis of the nine candidate genes, Glyma.19G230000 and Glyma.19G230200 were identified as potential regulators of plant height in soybeans. This study provides valuable materials and technical support for the cloning of plant height-related genes and the molecular breeding of soybeans.