Microbial capsule building block for repairing roadbed in water sensitive area and application of microbial capsule building block

The invention discloses a microbial capsule building block for repairing a roadbed in a water sensitive area and application of the microbial capsule building block. The microbial capsule building block comprises the following components in parts by mass: 30-40 parts of microbial capsules, 50-60 parts of soil and 40-45 parts of an alkali-activated cementing material, according to the microbial capsule, a water-soluble material is used as a capsule wall layer, and a mixture of sporosarcina pasteurii and urea is used as a capsule core layer; microbial capsules are buried in a roadbed of a water sensitive area road section in advance and used for preventing the roadbed from being possibly damaged by water when excessive water is accumulated on the road surface, underground water seepage or rainstorm weather comes, and the microbial capsules are dissolved under water soaking and activate bacteria to react to generate carbonate; and gaps are filled, so that the soil body is compact, the roadbed is automatically re