Abstract: 【Objective】The objective was to study the effects of pyrrolidine quinoline quinone on the growth and physiological responses of pepper under drought stress.【Method】By taking pot culture method, the effects of pyrroquinolinone quinone on the agronomic characters, proline, chlorophyll, soluble sugar, malondialdehyde, oxidase, photosynthetic characteristics and quality of pepper under different water conditions were studied.【Result】The results showed that low concentration (0-500 nmol/L) pyrrolidine quinoline quinine sprayed under drought stress had a certain effect on the drought resistance of pepper. It effectively inhibited the decrease of chlorophyll and soluble protein content, increased the content of proline and soluble sugar content. Antioxidant enzyme activity increased significantly, the degree of membrane lipid peroxidation decreased, and the photosynthetic characteristics enhanced. The net photosynthetic rate of 200 nmol/ L treatment increased by 130.89% compared with that of 0 nmol/L, and the fruit quality was partially improved. Spraying high concentration (1 000 nmol/L) pyrrolidone quinoline quinine inhibited pepper growth, and 200 nmol/L treatment was the most conducive to the drought resistance and growth of pepper.【Conclusion】In the actual production of pepper, it is recommended to spray the pyrrolidone quinoline quinone solution with a concentration of 200 nmol/L in the arid or semi-arid pepper planting areas.