The invention provides a winter wheat-summer corn rotation one-time fertilizing emission reduction method, and belongs to the technical field of farm fertilizing. The method considers the nutriment demand and allocation of two crops in one year. An organic fertilizer and a slow controlled-releasing nitrogenous fertilizer are mixed to be applied to winter wheat during N application of the winter wheat; and the fertilizing manner includes: smashing all the corn straw, returning the smashed straw to soil, performing rotary tillage, and applying the mixed fertilizer to the soil once. A slow controlled-releasing nitrogenous fertilizer provides N elements to summer corn, and is applied to the soil once with corn sowing on the primes of applying the sufficient organic fertilizer to the winter wheat. The times of field fertilizing is 2, labor forces can be greatly saved, soil disturbance is reduced, the emission of N2O is reduced, the use amount of the nitrogenous fertilizer is reduced by 14-25%, the yield of the two crops is increased by 400-500 kg/hm<2>, the average income is increased by 1400-1600 yuan/hm<2>, the fertilizer utilization rate is improved by 25-35%, labors can be saved by 30-45, and the emission of N2O is lowered by 25-35%.