The invention relates to a demonstration device, and particularly relates to a physical convex lens experimental demonstration device, so as to solve the technical problem of providing a physical convex lens experimental demonstration device with the advantages of intuitive demonstration, time and labor saving and small labor intensity. In order to solve the above technical problem, the invention provides the physical convex lens experimental demonstration device, which comprises a trolley, a first cylinder, a first sliding block, a side plate, a first sliding rail, a rack, a gear, a convex lens, a second cylinder, a push plate, a placement plate, a supporting rod, a first connection rod, an electric winding wheel, a pulling wire, a second sliding block, a spring, a second connection rod, a third cylinder, a third sliding rail and a processing box, wherein the trolley is sequentially provided with the side plate, the first cylinder, the supporting rod, the second sliding rail and the processing box sequentially from left to right; the first sliding rail is arranged on the side plate; the first sliding block is arranged on the first sliding rail; the upper end of the first cylinder is connected with the rack; and the first sliding block is connected with the rack. Effects of intuitive demonstration, time and labor saving and small labor intensity are thus achieved.