| Crop soil\|borne diseases have become a key factor limiting soil health, food security, and sustainable agricultural production in China. The occurrence of soil\|borne diseases is mainly caused by the deterioration of the soil environment caused by a large amount of chemical fertilizer, pesticide input, and single\|crop planting in the process of agricultural production, which leads to the negative feedback physiological and ecological effects of “soil\|root” interaction. The formation mechanism of this negative feedback effect is as follows: (1) Deteriorated soil properties will inhibit the growth and development of crop roots by limiting the absorption of water and nutrients by crop roots; (2) Deteriorated soil properties can cause an imbalance in the diversity and community structure of inter\|root soil microorganisms (fungi and bacteria) and provide a favorable environment for the propagation and growth of soil\|borne pathogens, resulting in weak and stunted crop roots being highly susceptible to infection and invasion of pathogens, leading to root rot and even death of the entire crop. Biochar has shown great potential in improving soil health, promoting crop growth, and inhibiting crop root diseases. Biochar improves soil physical, chemical, and microbial properties, including reducing soil bulk density, increasing soil porosity, enhancing soil water retention, adjusting soil pH, reducing nutrient leaching loss, increasing soil organic carbon content, and reducing soil abundance of Fusarium species, thereby reducing crop root diseases. Future research directions should focus on the “biochar\|soil\|microorganisms\|root disease” system, exploring the mechanism of biochar\|mediated plant resistance. |