The invention discloses a hydropower house foundation handling method which comprises the steps that A, multiple cement mixed grating piles are constructed to form a grating network; B, distribution piles are constructed in the middle of each grating of the grating network; C, high-pressure rotary spray connector piles are constructed at intersections of the longitudinal cement mixed grating piles and the transverse cement mixed grating piles; D, a plastic concrete diaphragm wall is constructed in a soil layer. By means of the hydropower house foundation handling method, the problems of insufficient bearing capacity, overlarge settlement deformation, a seepage failure and foundation vibratory liquefaction of a weak foundation of a hydropower house can be avoided, construction investment is low, construction is convenient and fast, and the method can be widely applied to the technical field of hydroelectric generation engineering.