This study investigates the growth-promoting effects of three Plant Growth-Promoting Rhizobacteria (PGPR) strains—FJS-3 (Burkholderia pyromania), FJS-7 (Pseudomonas rhodesiae), and FJS-16 (Pseudomonas baetica)—on tea, tobacco, and chili pepper plants. The PGPR strains were prepared into solid biological agents and tested in both greenhouse and field trials. In the greenhouse experiments, the PGPR treatments significantly enhanced the growth of tea seedlings, tobacco, and chili pepper plants, with FJS-3 showing the best growth promotion effect on tobacco. In the field trial, a multi-strain PGPR biological agent applied alongside compound fertilizer significantly increased tea yield and quality, particularly in terms of chlorophyll content and theanine levels, compared to treatments with only compound fertilizer or no fertilizer. The results demonstrate that the selected PGPR strains can effectively promote plant growth and improve crop yield and quality, suggesting their potential for practical application in agriculture.This study investigates the growth-promoting effects of three Plant Growth-Promoting Rhizobacteria (PGPR) strains—FJS-3 (Burkholderia pyromania), FJS-7 (Pseudomonas rhodesiae), and FJS-16 (Pseudomonas baetica)—on tea, tobacco, and chili pepper plants. The PGPR strains were prepared into solid biological agents and tested in both greenhouse and field trials. In the greenhouse experiments, the PGPR treatments significantly enhanced the growth of tea seedlings, tobacco, and chili pepper plants, with FJS-3 showing the best growth promotion effect on tobacco. In the field trial, a multi-strain PGPR biological agent applied alongside compound fertilizer significantly increased tea yield and quality, particularly in terms of chlorophyll content and theanine levels, compared to treatments with only compound fertilizer or no fertilizer. The results demonstrate that the selected PGPR strains can effectively promote plant growth and improve crop yield and quality, suggesting their potential for practical application in agriculture.