Bacteria that thrive in extreme environmental conditions possess unique abilities to promote plant growth and enhance disease resistance. In this study, a plant growth-promoting rhizobacteria (PGPR) was isolated and purified from the rhizosphere soil collected at the Red Beach of Panjin, designated as strain YB1701. Strain YB1701 was identified as Bacillus amyloliquefaciens, a gram-negative Bacillus, measuring between 1.6 μm to 3.1 μm in length and 0.9 μm to 1.1 μm in width. The optimal pH for strain YB1701 growth was determined to be between 7.0 and 8.0, and the strain exhibited a strong ability to degrade starch. The indole-3-acetic acid (IAA) content produced by the strain was 137.58 μg·mL⁻¹, and it showed 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of 3.03 μmol·mg⁻¹·h⁻¹. Strain YB1701 inhibited 16 different plant pathogenic fungi by at least 50%, with more than 80% inhibition observed against Exserohilum turcicum and Sclerotinia sclerotiorum. Additionally, treatment with strain YB1701 significantly promoted the growth of rice seedlings, increasing shoot height, root length, and shoot and root dry weight by 64.54%, 20.39%, and 71.94%, respectively. Root dry weight alone increased by 2.36%. These findings suggest that B. amyloliquefaciens strain YB1701 has potential applications in agriculture and other fields as a novel biocontrol agent and growth promoter. This strain could enrich microbial species resources and provide a basis for the utilization of bacterial resources in various applications.