Combined rotational molding box body

The utility model discloses a combined rotational molding box body which comprises a bottom plate and a connecting and fixing mechanism, the front side and the rear side of the upper surface of the bottom plate are each fixedly connected with two inserting columns which are symmetrically distributed left and right, first side plates are inserted between the outer arc faces of every two inserting columns which are adjacent left and right, and second side plates are slidably connected between the left sides and the right sides of the two first side plates. The edge of the upper end of the whole formed by the first side plate and the second side plate is movably sleeved with a connecting sleeve, the rear side face of the connecting sleeve is hinged to a top cover through a hinge, the inner walls of the left side and the right side of the connecting sleeve are fixedly connected with limiting ropes, the upper ends of the limiting ropes are fixedly connected with the top cover, and a sealing ring is arranged on the