Heavy-load plastic coaming box

The utility model discloses a heavy load type plastic coaming box which comprises a box body assembly, two limiting assemblies are installed on the positions, close to the top, of the outer walls of the two sides of the box body assembly through bolts, a box cover fixedly connected with the limiting assemblies is connected to the top end of the box body assembly in a clamped mode, a bottom plate assembly is connected to the interior of the box body assembly in a clamped mode, and the bottom plate assembly comprises a bottom plate. Supporting rods are welded to the two sides of the outer wall of the top of the bottom plate, clamping pieces are slidably inserted into the top ends of the supporting rods, the bottom plate comprises two base layers, a plurality of supporting pieces are welded between the two base layers, and the space between every two adjacent supporting pieces is filled with filler. When the coaming box is used for loading goods, the supporting piece is matched with the two base layers to form a