The utility model discloses a stably-assembled lampshade, which comprises a first bracket, a second bracket and a plastic cement mat coat clamped between the first bracket and the second bracket, wherein the plastic cement mat coat is cylindrical; upper clamping slots clamped with the first bracket are arranged on the inner side at one end of the plastic cement mat coat; and lower clamping slots and clamping grooves which are clamped with the second bracket are alternately arranged on the inner side at the other end of the plastic cement mat coat. The stably-assembled lampshade is very convenient to assemble and dissemble, thereby greatly facilitating the clean-up and repair of lamps for users; in addition, the stably-assembled lampshade has a simple structure; and the upper clamping slot and the lower clamping slots coordinate with the clamping grooves to clamp the brackets, so that the whole structure of the lampshade is very stable.