Bioremediation is an environment friendly and economically feasible remediation technology. Plant root exudates, playing an active role in root-microbe communications, are the key substances in bioremediation processes of soil contamination. Understanding the effects and mechanisms of plant root exudates on soil remediation can provide a better guidance with bioremediation techniques. Moreover, it is also helpful to understand the adapted mechanisms of plants and microbial communities in contaminated soils. In this paper, the effects of contaminants on the characteristics of root exudates, the effects of root exudates on the environmental behaviors of contaminants in soils were studied. Furthermore, the roles and mechanisms of root exudates in regulating the diversity of the rhizosphere microbial communities were also reviewed to reveal the effects and mechanisms of plant root exudates in the remediation of soil contaminants. The results indicated that root exudates played an important role in reducing the toxicity of metal(loid)s to plants, and also in accelerating the degradation of organic pollutants. Besides, root exudates had significant effects on the abundance and diversity of soil microorganisms. Interactions of root exudates with rhizosphere microorganisms played an important role in the reduction of soil contaminants. On this basis, current knowledge gaps and future research directions of root exudates under the stress of soil contaminants are also identified.