Abstract: To evaluate the effects of decomposed sheep manure with or without the addition of trace element fertilizer(1% ferrous sulfate, 0.5% manganese sulfate, 1% zinc sulfate and 0.5% borax, all by weight ratio)on the enzyme activity, microbiological characteristics and corn yield in aeolian sandy soil, a total of nine treatments were set up: no organic fertilizer treatment (CK), decomposed sheep manure application at 7 500 (SM1), 15 000 (SM2), 22 500 (SM3), 30 000 kg·hm^-2 (SM4) and decomposed sheep manure with trace element fertilizer application at 3% rate represented by SM1+TE, SM2+TE, SM3+TE and SM4+TE, respectively. The different treatments were compared to analyze their effects on soil urease, alkaline phosphatase, protease, sucrase and dehydrogenase activities, as well as microbial quantity, microbial carbon/nitrogen content and corn yield. The results show that, in the wind-sand area of Inner Mongolia Autonomous Region, compared with the control group without organic fertilizer (CK), the application of decomposed sheep manure and decomposed sheep manure with 3% trace element fertilizer also increased microbial quantity and microbial carbon/nitrogen content in the soil and improved urease, alkaline phosphatase, protease, invertase and dehydrogenase activities. Among the treatments, the best effect was observed with the application of decomposed sheep manure with 3% trace element fertilizer at a rate of 30 000 kg·hm^-2, which could increase the bacteria, fungi, actinomycetes and total microbial quantity in the soil by 2 to 3 times, and the microbial carbon/nitrogen content in the soil increased significantly by 3.40%-58.26% and 7.09%-82.22%, respectively. The activity of urease, alkaline phosphatase, protease, invertase and dehydrogenase also increased by 29.23%-108.26%, 51.92%-243.48%, 7.17%-145.89%, 20.78%-112.19% and 4.04%-201.75%, respectively. By using the membership function analysis method to comprehensively evaluate the soil fertility after applying different organic fertilizers, it was found that the treatment of applying 30 000 kg·hm^-2 decomposed sheep manure with 3% trace element fertilizer had the best fertility effect. The application of different organic fertilizers significantly increased maize yield by 16.70%-54.34%. Considering factors such as soil environment, corn yield and economic benefits, the application of decomposed sheep manure at a rate of 7 500 kg·hm^-2 with 3% trace element fertilizer is recommended as an effective measure to improve soil quality, crop yield and economic benefits in the local area. The correlation analysis results indicated a significant positive correlation between soil microbial carbon/nitrogen content, enzyme activity, microbial quantity and yield.