The invention relates to plant-microorganism combination remediation technologies of DDT-contaminated soil, in particular to a method and application for remedying DDT-contaminated soil through a plant-microorganism combination. According to the method and application for remedying the DDT-contaminated soil through the plant-microorganism combination, the DDT-contaminated soil is remedied in the manner that ryegrass is planted in the DDT-contaminated soil and DDT degrading bacteria and plant growth promoting rhizobacteria are exerted on the DDT-contaminated soil, then overground ryegrass is harvested, and DDT in the soil is removed. The method and application for remedying the DDT-contaminated soil through the plant-microorganism combination comprise the following steps that in a DDT-contaminated farmland greenhouse, before the ryegrass is planted, a plough layer of the soil is turned over and flattened manually, and the DDT degrading bacteria are added; the ryegrass is sown, weeding is conducted at regular intervals, and after the ryegrass grows for one month, the plant growth promoting rhizobacteria are added; the overground part and the underground part of the ryegrass are harvested; and the DDT contents of the overground part and the underground part of the ryegrass are measured, and the DDT removal amount of the soil is measured. By the adoption of the method and application for remedying the DDT-contaminated soil through the plant-microorganism combination, the DDT in the soil can be effectively removed, the degradation rate of the DDT is high, the DDT content of the overground part of the ryegrass is low, and the risk that the DDT enters a food cycle along with the plants is lowered; and the method is simple in operation, safe, high in efficiency, low in cost and high in economic and social benefit.