Carbon coupling composite microbial inoculum and preparation method and application thereof

The invention relates to the technical field of biomass resource utilization and environmental pollutant treatment, in particular to a preparation method of a carbon coupling composite microbial inoculum. The method comprises the following steps of: S1, treating a natural material capable of being carbonized; S2, collecting a soil sample of typical polluted point soil, and separating and culturing a target strain through an in-situ culture method; S3, performing domesticating to obtain a strain capable of degrading a target pollutant under the stress of heavy metal; S4, conducting separating and purifying to obtain a pure bacterial colony of the degrading bacteria; S5, repeating the S4, collecting at least three thalli, performing enrichment culture until OD600 is equal to 1.0-1.2, collecting bacterial liquid, and performing cryopreservation; S6, mixing various bacterial liquid to obtain a compound bacterial seed solution; and S7, performing mixed culture on the compound bacterial seed solution and a carbon-b