The utility model discloses a lock set assembly with a dustproof cover. Including a housing assembly, wherein the lock cylinder assembly is arranged in the shell assembly; the dustproof cover is arranged on the shell assembly; two mounting arms are arranged on the shell assembly; the dustproof cover comprises a dustproof cover main body and a mounting rotating shaft connected with the dustproof cover main body; a torsional spring is also arranged on the mounting rotating shaft; a pressing tongue is arranged in the middle of the torsional spring, a rear end face and a lower end face which are matched with the pressing tongue are arranged on the installation rotating shaft, the rear end face is of an inclined face structure inclining upwards, the included angle between the rear end face andthe horizontal plane ranges from 75 degrees to 78 degrees, and the included angle between the lower end face and the rear end face ranges from 85 degrees to 92 degrees. According to the utility model,the torsion spring is matched with the rear end surface and the lower end surface, so that the dustproof cover can be kept in an open state without being held by hand, and the key is convenient to open. The dustproof cover can be widely applied to the field of dustproof covers of lock set assemblies.