Recent studies show that biochar has significant effect on soil borne plant diseases prevention and control.In this paper,the mechanisms of diseases prevention and control by biochar are discussed from several topics,mainly on how biochar affects soil physical and chemical properties,changes soil microbial community structure and quantity,changes the number of soil pathogens,adsorbs the allelopathic substances produced by plant roots and pathogens secretions,and induces plant disease resistance.In addition,the impact of raw material,pyrolysis condition and utilization dose of biochar on disease control efficiency are investigated.This paper will provide theoretical support for biochar application in agriculture for soil borne disease control.