Portable warning board for highway construction

The utility model discloses a portable warning board for highway construction, which comprises a warning board body, sliding barrels are arranged at the left end and the right end of the bottom of the warning board body, sliding rods are inserted into the sliding barrels, limiting holes are formed in the upper end and the lower end of the left side wall and the right side wall of the warning board body, and the limiting holes penetrate through the interiors of the sliding barrels. A sliding groove is formed in the top end of the sliding rod, a sliding block is arranged in the sliding groove, the arc-shaped limiting protruding block is pressed to be separated from the limiting hole, at the moment, the sliding rod is contracted in the sliding barrel till the arc-shaped limiting protruding block reaches the interior of the limiting hole in the side wall of the top end of the warning board body, and at the moment, the arc-shaped limiting protruding block is limited. A sliding rod is limited in a sliding cylinder,