Starter culture significantly influences the texture and flavor of yogurt, making the selection of appropriate fermentation strains a key focus in yogurt starter research. In this study, protease-producing Lactiplantibacillus plantarum NH-24, identified in prior experiments, was combined with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophiles for yogurt fermentation. Indicators such as coagulation state, acidity, and water-holding capacity were measured to determine the optimal fermentation temperature and starter ratio. Additionally, the effects of this strain on the yogurt’s texture, sensory properties, and volatile flavor compounds were evaluated. The results indicate that a fermentation temperature of 37 °C and a starter ratio of 4:4:3 were most suitable for yogurt production. Further analysis demonstrated that incorporating Lp. plantarum NH-24 improved the yogurt’s texture and flavor while reducing post-acidification during storage. Thus, protease-producing Lp. plantarum NH-24 holds significant promise as a yogurt starter culture.