Disclosure is an assembled plastic tray. The plastic tray includes a mainboard and strakes fixed at two sides of the mainboard. The mainboard includes two rib frames and multiple strip-shaped pad feel uniformly distributed between the two rib frames. The steps for assembling the plastic tray includes: respectively inserting first mainboard steel tubes and second mainboard steel tubes into first mainboard steel tube holes and second mainboard steel tube holes of the rib frames on the mainboard, subsequently, mounting the two strakes on the two side surfaces of the mainboard through a boss and penetrating slots and fixing the boss and the penetrating slots through strake connection blocks, then inserting strake steel tubes into strake steel tube holes on the two strakes, and then, fixing the strake steel tubes and the first mainboard steel tubes through steel tube connection members and steel blocks.