The invention discloses a method for treating a deep loose and soft rock stratum roadway floor heave through jet grouting piles. The method comprises the steps that firstly, the lithology of a floor rock stratum is detected to determine the position of a floor key layer, jet grouting pile sets are arranged on all cross sections of segments, prone to being subjected to the floor heave, along a deepwell soft broken rock stratum roadway floor at fixed intervals, the 3-5 jet grouting piles are symmetrically constructed to the two sides of each cross section with the center of the roadway cross section as the boundary at intervals, and the 45-degree base angle jet grouting piles and the 0-degree vertical jet grouting piles are distributed on the same cross section. According to the method fortreating the deep loose and soft rock stratum roadway floor heave through the jet grouting piles, the pressure transmission path of the two sides of a roadway to the floor can be cut off, squeezing formed to the floor is weakened, and deformation is inhibited; the floor rock stratum is detected in advance so that the jet grouting piles can be reinforced to the floor hard rock stratum; and the problem of reinforcing of the loose and broken roadway floor with poor anchability and groutability is solved, under the condition that an original structure of the roadway is not destroyed, strong reinforcing measures are taken on the original loose rock stratum, the construction difficulty cannot be increased with increasing of the mining depth, and the stability of the roadway is improved comprehensively.