The mechanism of microbial degradation of 1,2,4-trichlorobenzene includes aerobic degradation, reductive dechlorination and co-metabolism. This paper provided a brief review of the research progress in the biodegradation of 1,2,4-TCB. The potential biodegradability was analyzed. The pathway of aerobic degradation of 1,2,4-TCB and the related microbial strains, as well as the reductive dechlorination of 1,2,4-TCB by microbial community or single strain were discussed. The aim of this paper is to provide a guide for microbial remediation of 1,2,4-TCB contaminated soil.