The invention relates to a horizontal-shaft tidal turbine with linkage spiral vanes. The horizontal-shaft tidal turbine comprises a spindle, a case, a thrust bearing, a coupling, a generator, a rack, a base and a water guide cone, wherein the lower side of the case is respectively supported by the rack and the base; the horizontal-shaft tidal turbine is characterized by further comprising linkage spiral vanes in two-dimensional linkage spiral line shape, a cone-like-shaped hub immersing into tide, and a sealing cover; the generator is connected with the spindle and the cone-like-shaped hub by the coupling, the sealing cover is arranged at the junction of the spindle and the cone-like-shaped hub, the water guide cone is arranged at the tail part of the case at the rear side of the cone-like-shaped hub; and the linkage spiral vanes rotate at uniform speed at the periphery of the cone-like-shaped hub by forming gradient stretching along the axial direction of the cone-like-shaped hub to form a spatial warping shape to be uniformly distributed via the thrust bearing. The horizontal-shaft tidal turbine can greatly reduce hydraulic friction collision and reduce loss at the entrance head, thus improving the capacitation effect of the water turbine and well solving the difficulty of allowing ocean fish schools to smoothly pass.