The utility model discloses a multipurpose floorslab negative-reinforcement protection support, which comprises a square framework formed by connecting two longitudinal frames and two transverse frames, wherein the two longitudinal frames are connected with each other by a plurality of intermediate connecting frames that are arranged in parallel; and a plurality of legs are connected on the two longitudinal frames along the vertical direction. With the adoption of the multipurpose floorslab negative-reinforcement protection support, the thickness of concrete on a floorslab can be ensured, and a negative bending reinforcement of the floorslab does not deform, can be taken as a transportation channel and can also be used in a turnover way.