The invention discloses a deep fractured surrounding rock composite grouting reinforcement method which comprises the following steps: S1, partitioning a deep fractured surrounding rock, and dividing the deep fractured surrounding rock into a completely fractured region, a fractured reduction region, a fractured compression region and a
protolith-like region according to the degree of fracture; S2, based on the
zoning result of the deep broken surrounding rock, performing
slurry permeability characteristic
zoning on each broken surrounding rock zone to obtain a
slurry high-permeability zone, a
slurry medium-permeability zone and a slurry low-permeability zone; S3, performing a grouting test on the construction site, and determining the grouting pressure and the drilling row
pitch of each permeability characteristic subarea; S4, selecting a corresponding grouting material for each
grout permeability characteristic subareasaccording to the fracture development degree; and S5, conducting drilling and grouting operation on the deep fractured surrounding rock subareas, and injecting each grouting material into the corresponding
grout permeability characteristic subareas. According to the method, surrounding rocks form a net-shaped structure with interlaced slurry veins through multiple grouting
modes and grouting materials, and the
mechanical property of a consolidated body is greatly improved.