The utility model relates to a compression clearance volute of a water turbine. The compression clearance volute of the water turbine comprises a metal volute and concrete on the periphery of the metal volute, wherein a straight pipe section is arranged at the inlet end of the metal volute, a water diversion steel pipe is connected with the straight pipe section of the inlet end of the metal volute, a worm type 0-degree fracture surface is arranged at the tail end of the straight pipe section, and a seat ring is arranged on the worm-shaped inner circle of the metal volute structure. The compression clearance volute of the water turbine is characterized in that a soft materials is fixed between the metal volute and the concrete on the periphery of the metal volute, plastic deformation is generated after the soft material is pressed, then a compression clearance is formed, the power transmission coefficient of the soft material is not larger than 50 MPa/m, the modules of deformation of the soft material ranges from 0.05 Mpa to 0.5 Mpa, and the thickness of the soft material is not larger than 10 mm. According to the compression clearance volute of the water turbine, problems existing in the aspects of the mechanical stability abd the durability of a cushion material in a cushion volute structure in the full life circuit of the volute structure are solved, the integrality of the volute structure is improved, and long-term safe and stable operation of a hydropower unit is facilitated; the manufacturing cost is low, construction is easy and convenient, and the requirements for hydropower station volute structures of various faucets can be met.