The utility model discloses an anti-upwarp clamp for a scaffold board. The anti-upwarp clamp is characterized in that a lower frame compression bar with side ears on two ends is made of a strip steel plate in a bending manner, the lower frame compression bar compresses on the scaffold board in a buckling manner, through holes are formed in the side ears, J-shaped bolts penetrate through the through holes to be fixedly arranged on the side ears through fastening nuts, and steel pipes of a scaffold are fixed in hook heads of the J-shaped bolts in a clamping way. The anti-upwarp clamp is applied to the scaffold board on the scaffold, so that the upwarp of the scaffold board is prevented, the structure is simple, the manufacture is easy, the assembly and disassembly process is extremely convenient, and the anti-upwarp clamp can be repeatedly utilized.