Quantitative compensation supporting method for soft rock large-deformation tunnel

The invention relates to the field of tunnel construction, in particular to a soft rock large-deformation tunnel quantitative compensation supporting method which comprises the following steps that S1, the reserved deformation amount of a tunnel is determined; s2, the actual deformation of the tunnel is controlled within the reserved deformation, and the method comprises the following steps that S21, a long pipe shed is constructed on the periphery of the tunnel excavation outline, the length of the long pipe shed is larger than 30 m, and in the embodiment, the length of the long pipe shed is preferably 55 m; s22, performing primary support, wherein the structure of the primary support comprises a steel arch; s23, monitoring and judging whether the steel arch is deformed or not, and outputting a deformation result; if yes, S24 is carried out; if not, concrete spraying operation is carried out; and S24, anchor rods are applied to the surrounding rock supported by the deformation position of the steel arch acco