The invention belongs to an efficient hydraulic model for a centrifugal type pump, particularly relates to a hydraulic model of a CAP1400 reactor coolant pump and a design method of the hydraulic model, and is applicable to design of a hydraulic model of a reactor coolant pump product for a third-generation nuclear reactor system. The hydraulic model comprises a pump shell, an impeller, guide vanes, a heat shield and a suction guide pipe, wherein the suction guide pipe is located at the suction end position of the pump shell; the impeller is in clearance fit with the suction guide pipe; the guide vanes are arranged at an outlet of the impeller; and the guide vanes and the heat shield are welded into a whole to form a fluid discharging path together with the outlet of the pump shell. The pump specific speed ns of the hydraulic model is 475 to 490, the flow Q is 20927<+4%>-6% m<3>/h, the total lift H is 104.2+/-2% m, the number of rotations n is 1787, and the efficiency (eta) is more than or equal to 0.82. By adoption of the efficient hydraulic model disclosed by the invention, the reactor coolant pump is relatively high in operation efficiency and large in working condition range.