Abstract: 【Objective】This study aimed to investigate the control mechanism of maize straw biochar on konjac soft rot，providing technical parameters and theoretical support for efficient resource transformation of agricultural waste as well as green control and synergistic enhancement of konjac soft rot.【Method】Maize straw biochars prepared at different pyrolysis temperatures （350 and 500 ℃） were taken as research subjects. The microstructure of biochars was characte-rized by scanning electron microscopy （SEM） and specific surface area analysis. Antibacterial tests in sterilized soil were conducted to determine inhibitory effects of biochars at different pyrolysis temperatures （350 and 500 ℃） and additive amounts of biochar （0-100 g/kg） on soft rot pathogens. Illumina MiSeq high-throughput sequencing was used to analyze the changes in rhizosphere soil bacterial and fungal community structures under 4%-8% （w/w） biochar additive amounts， and LEfSe analysis was used to screen differential functional microbiotas.【Result】The biochar pyrolyzed at 500 ℃ exhi-bited nano-micron multi-level pore structures，with a specific surface area of 218.6 m²/g， which was about 3.8-fold higher than that of the biochar pyrolyzed at 350 ℃ （57.4 m²/g）， and its pore volume increased by 5.2-fold，which showed better inhibitory effects than the biochar pyrolyzed at 350 ℃. When the additive amount of biochar pyrolyzed at 500 ℃ was 100 g/kg， konjac soft rot pathogen growth was completely inhibited，whereas at the same additive amount of biochar pyrolyzed at 350 ℃， the inhibitory rate was 78.4%. Regarding microbiota regulation，with the increase of biochar additive amount，the relative abundance of Bacilli in bacterial communities increased from 5.89% in control （with biochar additive amount of 0） to 49.03% at the additive amount of 8%； the relative abundance of soft rot pathogen belonged to Gammaproteobacteria decreased from 5.60% to 0.03%； the relative abundance of Sordariomycetes in fungal communities increased from 20.47% in control to 46.41% at the additive amount of 8%. LEfSe analysis showed that biochar reconstructed the rhizosphere microecological balance by promoting the proliferation of functional microbiotas such as Firmicutes.【Conclusion】The biochar pyrolyzed at 500 ℃ of maize straw controls konjac soft rot through a dual mechanism of physical adsorption and biological regulation. The combination of biochar pyrolyzed at 500 ℃ of maize straw （at an additive amount of 4%-6%） and Bacilli agent is recommended for field application， as it can synergistically improve the control effects on konjac soft rot.