Abstract: Taking greenhouse pepper as materials,the photosynthetic characteristics,yield and quality of pepper under different fertilization treatments were studied by using conventional determination method,in order to provide scientific basis for rational fertilization of pepper.The results showed that with the increase of the amount of biological fertilizer instead of chemical fertilizer,the plant height,plant width,fruit length,fruit thickness,single fruit weight,net photosynthetic rate,stomatal conductance,transpiration rate,vitamin C content,capsaicin content and soluble sugar content showed an upward trend,and the intercellular CO₂ concentration showed a downward trend.Compared with CK,the plant height of peppers in SQH10,SQH20,SQH30 and SQH40 increased by 10.75%,16.26%,17.47% and 16.67% respectively,the plant width increased by 2.92%,5.86%,6.30% and 5.56% respectively,and the single fruit weight increased 3.34%,12.86%,12.72% and 12.69%,the net photosynthetic rate increased by 10.80%,17.43%,18.65% and 16.59% respectively,the output increased by 13.74%,27.34%,28.76% and 28.56%,and the vitamin C content increased by 6.40%,11.71%,11.05% and 8.35%,capsaicin content increased by 4.69%,7.17%,7.03% and 6.59%,soluble sugar content increased by 5.56%,10.94%,10.28% and 10.40%.In summary,the combined application of biological bacterial fertilizer improved the growth performance,photosynthetic characteristics and yield of pepper,and improved the quality.The growth performance,photosynthetic characteristics,yield and quality of pepper treated with SQH30 were the best,that was,the biological bacterial fertilizer replaces the chemical fertilizer by 30%,should be promoted in actual production.