The utility model discloses a multifunctional safety sign for construction, which relates to the technical field of construction warning devices, and comprises a warning sign, a support rod, a rotating shaft, a circular groove, an inserting shaft, a plurality of spherical bulges and a second rotating rod, the upper end of the support rod is rotatably connected with a first rotating rod, the rotating shaft penetrates through the support rod and the first rotating rod, and the rotating shaft is rotatably connected with the support rod; the rotating shaft is rotatably connected with the first rotating rod, the circular groove is formed in the lower end of the first rotating rod, a plurality of clamping grooves are evenly formed in the side wall of the circular groove in the circumferential direction, the inserting shaft is fixedly connected with the upper end of the supporting rod, the inserting shaft is coaxially inserted into the circular groove, the plurality of spherical protrusions are evenly connected to the outer side of the inserting shaft in the circumferential direction, and the spherical protrusions are matched with the clamping grooves. The multifunctional warning board can be applied to the flat ground and can also be stably placed on the inclined ground, the angle of the warning board can be adjusted, and therefore the multifunctional warning board has the advantages of being multifunctional, good in adaptability and convenient to operate.