Abstract: Successive cropping obstacle is a typical negative plant-soil feedback phenomenon, which has long plagued the development of agricultural production, and the occurrence mechanism and control measures of successive cropping obstacle have been research focuses of domestic and foreign scholars. Autotoxcity is one of the occurrence mechanisms of successive cropping obstacle, the accumulation of autotoxins affects nutrient absorption, photosynthesis and enzyme activity, then inhibits crop growth. Meanwhile, autotoxin decreases soil microbial activity and diversity, enhances the growth of pathogenic bacteria and soil- borne diseases by changing microflora, then leads to an increased degree of soil sickness. Intercropping accords with the idea of sustainable development of modern agriculture, using plant allelopathy can provide nvironmental, economical and effective approaches to control successive cropping obstacle. The authors analyzed resistance enhancing from crop nutritional and hysiological aspects, clarified the mechanism of successive cropping obstacle alleviation by intercropping from the interaction of rhizosphere microorganisms, autotoxins and pathogens. The results could provide references for the understanding of underground ecological processes in intercropping and the release of successive cropping obstacle, to formulate reasonable intercropping mode. The study is helpful to reveal the feedback mechanism between the ground and underground biodiversity.