To solve the problems of yield reduction and excessive greenhouse gas emissions caused by the excessive application of chemical fertilizers in the Hexi Oasis Irrigation Area，the effects of different amounts of chemical fertilizers on wheat yield and the ecological effects after the long-term turning of green manure were explored.Based on the long-term positioning test of Wuwei Oasis Agricultural Comprehensive Experiment Station in Gansu Province(started in 2009)，a total of eight treatments were set up，including no fertilizer control(CK)，100% chemical fertilizer(CF)and reduced chemical fertilizer application by 0%，10%，20%，30%，40%，100%(represented by MFR0，MFR10，MFR20，MFR30，MFR40，MFR100，respectively).In 2023，the differences in wheat yield，greenhouse gas emissions，and nitrate-nitrogen leaching between different treatments were compared，and a life cycle assessment(LCA)was used to quantitively assess the carbon footprint of different treatments.The results showed that compared with CF treatment，long-term green manure turning promoted wheat growth and significantly increased wheat yield with 40% reduction or less in chemical fertilizer.Compacting green manure significantly reduced the content of nitrate nitrogen in 0-20 cm soil layer by 52.61%-67.52%，and then reduced the leaching of nitrate nitrogen.Compared with the CK and CF treatments，it increased the soil CO₂ emission flux in the early stage，up to 220.2% and 136.5%，respectively，reduced the soil absorption of CH4.The cumulative emission of N2O showed a decreasing trend with the increase of the proportion of fertilizer reduction，and MFR40 treatment was reduced by 21.1%，compared with CF treatment.The soil organic carbon fixation was significantly increased under the green manure treatment.The global warming potential and greenhouse gas emission intensity showed a decreasing trend with the increase of the amount of chemical fertilizer reduction.The amount of chemical fertilizer reduction reached 30%，the value was negative，showing a trend of reducing global warming potential.Compared to CF treatment，turning green manure significantly increased the carbon footprint under the same amount of chemical fertilizer application.However，the production and transportation of chemical fertilizers，particularly nitrogen fertilizers，were the main contributors to the carbon footprint，the relative contribution rate was 24.6%-33.8%(except for CK and MFR100 treatments)，and the carbon footprint decreased with an increase in fertilizer reduction. Compared to the CF treatment，MFR20，MFR30 and MFR40 treatments were significantly reduced by 5.2%，11.3% and 17.7%，respectively.Reducing the amount of chemical fertilizer by 30% to 40%，after returning 30000 kg·hm-2 of green manure，could significantly increase wheat yield，reduce greenhouse gas emissions and carbon footprint，and reduce nitrate-nitrogen leaching.It was an effective measure to optimize wheat fertilization in the Hexi Oasis Irrigation Area.