The invention discloses a blockage-preventive floor drain which comprises a cylindrical shell. A plurality of first through holes are formed in the top of the shell, a water drainage port is arranged on the side face of the shell, a first rotating shaft is rotatably arranged at the top of the shell and peripherally provided with a winding rod and an impeller, a first sliding groove is axially formed in the periphery of the first rotating shaft, a plurality of blades are slidably arranged in the first sliding groove and fixed on an annular blade frame, a plurality of second sliding grooves are vertically formed in the inner side of the shell, a sliding strip is slidably arranged in each second sliding groove, and the upper ends of the sliding strips are jointly connected with a sliding ring which is rotatably connected with the blade frame; a fixing plate is arranged in the shell, a spring is arranged between the fixing plate and the sliding ring, a wire winding wheel is arranged at the bottom of the first rotating shaft, an annular third sliding groove is formed in the wire winding wheel, a slider is arranged on the third sliding groove and connected with the sliding strips through stay cords, and an elastic bent piece is arranged on the wire winding wheel. The blockage-preventive floor drain can effectively prevent floor drains and sewer lines from being blocked by hair.