The invention relates to the field of building construction, and in particular to a blockage preventer for grouting sleeves of prefabricated parts. The blockage preventer for the grouting sleeves of the prefabricated parts relates to a grouting section-sealing assembly which blocks a grouting section of a grouting sleeve, the grouting section-sealing assembly comprises a rubber base and a rod, the rod is connected with the base, the rod is located in the grouting section, the base is embedded in an opening of the grouting section, the rod is provided with two through holes, and the two through holes respectively correspond to the positions of a grouting hole and a grout discharge hole; two sets of hole-sealing assemblies are respectively plugged in the grouting hole and the grout discharge hole, each hole-sealing assembly comprises a rubber sealing base and a sealing rod, the sealing rods in the grouting hole and the grout discharge hole are respectively correspondingly inserted in the two through holes, and the sealing bases connected to the sealing rods are respectively plugged in the openings of the grouting hole and the grout discharge hole. The blockage preventer for the grouting sleeves of the prefabricated parts is simple in structure and easy to operate, prevents problems, such as the trouble of later cleaning due to grout leakage caused by the conventional process, can increase working efficiency, and ensures that the grouting sleeve cannot be stained.