The utility model belongs to the field of railway tunnel supporting structures, and relates to a large soft rock deformation tunnel supporting structure based on controllable deformation release, which is characterized in that a multilayer supporting structure is formed by sequentially connecting an advance condulet, an advance flexible net structure shield, a controllable deformation releasing space, an initial support, a water-proof plate and mold-injecting secondary lining concrete, wherein the advance flexible net structure shield consists of a net structure grating steel frame, a radial fixed anchor rod, a reinforcing mesh piece and injection concrete; the initial support consists of a profile steel frame, a system anchor rod, a double-layer reinforcing mesh piece, a foot-locking anchor tube and injection concrete; and the controllable deformation releasing space is internally filled with macromolecule elastic materials, so that the phenomena such as surrounding rock collapse, supporting structure damage, lagging jack detachment and replacement and the like due to the large deformation of a weak surrounding rock tunnel under complicated geological conditions can be avoided, and the surrounding rock stress cab be effectively reduced.