Abstract: 【Objective】 This experiment aims to explore whether microorganisms with different functions can stably exist in an organic-inorganic liquid compound fertilizers under a hypertonic environment, and the effects of different concentrations of bacterial liquid and organic-inorganic compound fertilizers on the quality and physiological activity of tomato fruit influence in the hope of providing theoretical data for organic tomato planting and quality improvement and preservation based on bio-organic-inorganic compound fertilizers. 【Methods】 Bacillus with different functions were connected to the same amount of organic-inorganic liquid compound fertilizers shake flasks in the form of spores, and stored at room temperature. The total number of colonies was regularly detected by the plate counting method, and the strains with good tolerance and high stability were screened out. Then this strain was used to prepare biological organic-inorganic liquid compound fertilizers in different concentration ratios. Starting from the two-ear period of tomato, bio-organic-inorganic liquid compound fertilizers and conventional fertilizers were applied every 10 days. After 49 days, the difference in tomato fruit quality and physiological activity was detected. 【Results】 Bacillus velezensis LYT-5 had the strongest stability among organic-inorganic liquid compound fertilizers, and strong resistance to stress in a hypertonic environment, and could be effectively compounded with organic-inorganic liquid compound fertilizers. Compared with the control (conventional fertilizers, 300 kg/hm²): T₃ (organic-inorganic liquid compound fertilizers, 300 kg/hm² + bacterial solution, 15 L/hm²) had the highest comprehensive improvement in fruit quality after 49 days. The average weight of single tomato fruits increased by 15 %, fruit shape index increased by 13 %, soluble polysaccharide content increased significantly by 43 %, sugar-acid ratio increased by 13 %, soluble protein increased by 6 %, which were suitable for short-term consumption and processing, etc.; and organic-inorganic after 49 days of treatment with functional bacteria of liquid compound fertilizers, tomato fruit onphenylalanine ammonia-lyase activity increased by up to 220 %, and ascorbate peroxidase activity increased by up to 21 %, which effectively improved the stress resistance and storage capacity of tomato fruits. 【Conclusion】 A functional strain that can stably exist in organic-inorganic liquid compound fertilizers and that has higher activity is screened out, and the concentration is T3 (organic-inorganic liquid compound fertilizers, 300 kg/hm² + bacterial solution, 15 L/hm²). It can obviously increase the yield and quality of tomato fruit after being applied at the same time, and reduce the loss after picking, which provides basic theoretical data for the research and application of biological organic-inorganic liquid compound fertilizers.