The invention discloses a cover plate moving device based on a rhombic elevating mechanism and a screw mechanism. The cover plate moving device comprises a concrete tunnel which is poured on a soil pit; a cover plate is arranged on the concrete tunnel; the cover plate moving device also comprises rhombic elevating mechanisms, a pulley mechanism, a driving mechanism and a screw hand wheel mechanism; an external driving mechanism is connected with the rhombic elevating mechanisms through the driving mechanism; the rhombic elevating mechanisms are respectively fixedly mounted at the middle sections of two inner walls, in the length direction, of the concrete tunnel; a track comprises a long track and a short track; the bottom of a left side cover plate block and the bottom of a right side cover plate block are each provided with a slider; the sliders and the long track form a leftward and rightward moving pair. The cover plate moving device based on the rhombic elevating mechanism and the screw mechanism, provided by the invention, is convenient to overhaul, relatively low in cost and relatively high in work efficiency.