The invention discloses a protective structure used for reinforcing an expansive soil slope. The protective structure comprises a plurality of anchor rods and a framed girder structure. The framed girder structure is laid onto the expansive soil slope. Each anchor rod comprises a rod body and an end cover mechanism. One end of each rod body is provided with an anchor head, and the rod bodies and the anchor heads are arranged inside the expansive soil slope in the protecting state of the expansive soil slope. Each end cover mechanism is arranged at the other end of the rod body of the corresponding anchor rod and further comprises two base plates which are arranged in parallel. A plurality of elastic parts and a plurality of supporting rods are arranged between the base plates. Connecting rods are arranged between the multiple supporting rods. By adoption of the protective structure, the anchor rods and the framed girder structure are adopted for combination, apart from the function ofrigid slope stabilization, expansion potential energy can be stored during water absorbing expansion of the expansive soil slope, stress-strain on the rigid supporting structure can be reduced, and the separating phenomenon of the slope and the supporting structure is prevented. The construction method is easy and convenient to operate and high in adaptive capacity.