Abstract: The present invention relates to a bicycle chain hanger, comprising a gear set, a slide bushing, a spring, a nut, and a quick removal wrench. The improvement comprising the gear is provided with wheel covers, inner rings, and snap rings on the two sides, a slide bushing passes through the inner ring, the middle section of one end of the slide bushing is provided with an outer expansion ring so that a spring can be put on the front screw of the quick removal wrench and locked with the nut on the other end through the bore of the bushing, therefore limiting the gear to rotate between the outer expansion ring and the nut; then, the other end of the slide bushing is put into the rear wheel axle hook of the bicycle and positioned with the quick removal wrench to replace the change gear set so that the chain can be cleaned conveniently.