Abstract: To study the strength and deformation properties of fibre-reinforced coral sand, conventional triaxial and hollow torsional shear tests and non-coaxial computational modelling of coral sand with different densities and polypropylene fibre dosage were carried out. The results show that: (1) Compared with the coral sand, the strength of polypropylene fibre coral sand is significantly improved, and the best fibre doping is around 0.3%, and the strength of fibre-reinforced coral sand is better when the densification is 65%. (2) Under the rotation of the main stress axis, the shear strain of the reinforced coral sand decreases with the increase of compactness, and the volume of the coral sand slightly expands after the rotation of 90°, and the non-coaxial angle generally shows a tendency of decreasing and then increasing, and the higher the compactness is, the stronger the coral sand coaxiality is. (3) A non-coaxial angle calculation model of fibre-reinforced coral sand was established by considering the co-axial and non-coaxial coupling deformation, and the test data verified the accuracy of the non-coaxial angle calculation model of fibre-reinforced coral sand.