An assembled plastic tray, comprising a mainboard and strakes, each with a first side surface, fixed at two opposite sides of the mainboard, the mainboard comprising a rib frame and a plurality of strip-shaped pad feet fixedly connected under the rib frame, and the assembled plastic tray further comprising first mainboard steel tubes, second mainboard steel tubes, strake steel tubes, steel tube connection members and steel tube blocks; wherein, the strip-shaped pad feet are all provided with second mainboard steel tube holes for mounting the second mainboard steel tubes, two ends of each of the second mainboard steel tubes extend out of the corresponding second mainboard steel tube hole, each of the strakes is provided with a placement groove corresponding to each of the second mainboard steel tube holes of the strip-shaped pad feet, and the second steel tube holes are arranged away from the rib frame; and opposite two side surfaces of the rib frame facing the strakes are both provided with penetrating slots; two ends and a middle portion of the other opposite two side surfaces of the rib frame are each at least provided with one first mainboard steel tube hole for mounting the first mainboard steel tubes, and the first mainboard steel tube holes and the second mainboard steel tube holes are orthogonal and penetrate through the rib frame; each of the strakes, along a length direction, is provided with a strake steel tube hole for mounting a strake steel tube, the strake steel tube hole penetrates through opposite second side surfaces of each of the strakes, said first side surface of each of the strakes coupled to the rib frame is provided with a boss matched with the corresponding penetrating slot of the rib frame, and the boss is inserted into the corresponding penetrating slot to connect the mainboard with each of the strakes through a strake connection block; two ends of each of the first mainboard steel tubes located at two ends of the rib frame and two ends of each of the strake steel tubes are respectively connected through the steel tube connection members, an outer side of each of the steel tube connection members is provided with a corresponding steel tube block connecting each of the steel tube connection members with the mainboard and the corresponding strake. the strip-shaped pad feet are all provided with second mainboard steel tube holes for mounting the second mainboard steel tubes, two ends of each of the second mainboard steel tubes extend out of the corresponding second mainboard steel tube hole, each of the strakes is provided with a placement groove corresponding to each of the second mainboard steel tube holes of the strip-shaped pad feet, and the second steel tube holes are arranged away from the rib frame; and opposite two side surfaces of the rib frame facing the strakes are both provided with penetrating slots; two ends and a middle portion of the other opposite two side surfaces of the rib frame are each at least provided with one first mainboard steel tube hole for mounting the first mainboard steel tubes, and the first mainboard steel tube holes and the second mainboard steel tube holes are orthogonal and penetrate through the rib frame; each of the strakes, along a length direction, is provided with a strake steel tube hole for mounting a strake steel tube, the strake steel tube hole penetrates through opposite second side surfaces of each of the strakes, said first side surface of each of the strakes coupled to the rib frame is provided with a boss matched with the corresponding penetrating slot of the rib frame, and the boss is inserted into the corresponding penetrating slot to connect the mainboard with each of the strakes through a strake connection block; two ends of each of the first mainboard steel tubes located at two ends of the rib frame and two ends of each of the strake steel tubes are respectively connected through the steel tube connection members, an outer side of each of the steel tube connection members is provided with a corresponding steel tube block connecting each of the steel tube connection members with the mainboard and the corresponding strake.