Multistage expansion type trolley

The invention discloses a multistage expansion type trolley. The trolley comprises a cargo carrying platform, a grab rail installed on the cargo carrying platform and used for pushing and pulling, andwalking wheels installed at the lower side of the cargo carrying platform, the cargo carrying platform is of a folding structure composed of a bearing plate and expansion plates arranged on the leftside and the right side of the bearing plate, the left expansion plate is hinged to the left edge of the bearing plate, the right expansion plate is hinged to the right edge of the bearing plate, andopening and closing limiting devices used for limiting the opening angles of the expansion plates are arranged between the expansion plates and the bearing plate; the left expansion plate and the right expansion plate are respectively provided with tooth parts which are matched with each other; drawing grooves with backward openings are formed in the bearing plate and the expansion plate, and drawing plates in sliding fit w