Granite　residual　soils　are　highly　susceptible　to　softening　and　disintegration　when　exposed　to　water,　extremely　easy　to　cause　geological　disasters.　Biomineralization　can　be　a　promising　method　to　improve　the　anti-disintegration　of　granite　residual　soils.　However,　due　to　the　low　permeability　of　the　soil,　it　may　be　difficult　to　effectively　or　efficiently　improve　the　anti-disintegration　of　granite　residual　soils　using　conventional　premix　or　spray　methods.　This　study　proposes　a　premix–spray　biomineralization　method　to　improve　the　anti-disintegration　of　granite　residual　soils.　The　bacterial　suspension,　bioslurry,　and　crude　soybean　urease　solution　were　used　as　the　urea　hydrolysis　media　in　this　study.　The　biomineralization　of　granite　residual　soils　by　premix,　spray,　and　premix–spray　methods　was　compared　based　on　the　disintegration　test　and　calcium　carbonate　content　measurement.　The　scanning　electron　microscope　observation,　energy-dispersive　X-ray　spectroscopy,　and　X-ray　diffraction　were　also　conducted　to　clarify　the　microscopic　characteristics　of　the　biotreated　granite　residual　soils.　The　test　results　indicate　that　the　premix–spray　method　could　effectively　improve　the　anti-disintegration　of　granite　residual　soil,　and　the　bioslurry　is　the　optimal　urea　hydrolysis　medium　for　the　premix　treatment.　The　sample　prepared　by　premixing　with　bioslurry　followed　by　3　cycles　of　spray　treatment　could　remain　relatively　stable　with　no　apparent　disintegration　or　cracking　within　24 h　of　immersion.　The　underlying　mechanisms　for　the　anti-disintegration　improvement　of　granite　residual　soils　with　biomineralization　may　mainly　include　the　pore　filling,　encapsulating　bonds　between　soil　particles,　and　biocementation　of　adjacent　soil　particles　by　the　precipitated　calcium　carbonate　crystals.　©　The　Author(s),　under　exclusive　licence　to　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2024.