Abstract: In order to verify the application effect of microbial agents in millet production, and screen out the best microbial agents, with Nenxuan 21 as the experimental material, a field experiment was conducted to set up six treatments: irrigation with five microbial agents（Bacillus subtilis, Trichoderma harzianum, Bacillus licheniformis, Bacillus amyloliquefaciens and compound microbial agents） and no microbial agents（CK） at seedling stage.The agronomic traits, yield traits, photosynthetic characteristics, soil nutrient content, enzyme activity and other indicators of millet under different treatments were analyzed.The results showed that compared with CK, the contents of total nitrogen, available phosphorus and available potassium in soil were significantly increased, and the activities of urease, invertase and neutral phosphatase were significantly enhanced after applying microbial agents.All five microbial agents can significantly improve the agronomic traits（ear length, ear diameter, plant height and stem diameter）, yield traits（ear weight and grain weight perear） and photosynthetic characteristics（net photosynthetic rate, transpiration rate and intercellular CO₂ concentration） of Nenxuan 21, but had no significant effects on 1000-grain weight.Among the tested inoculant treatments, the composite microbial inoculant treatment had the best effect on improving soil fertility and enzyme activity, and the highest millet yield, 16.86% higher than CK, and 24.21% higher net yield.Therefore, the compound microbial agent has a good application effect on corn, and can be applied to high-yield cultivation of millet in Heilongjiang.