A baffle plate operating mechanism for an exhaust which is connected an engine installed on a motor vehicle, e.g. motorcycles or automobiles, the baffle plate operating mechanism comprises a solid sleeve passing through and welded into the multiple layers of the muffler, a plurality of bushings mated in the solid sleeve and having a slit respectively, a shaft inserted into the sleeve, and a baffle plate mounted on the shaft and disposed inside the muffler. When the hot air exhausts from the engine, the solid sleeve isolate the thermal deformation between the multiple layers; and the bushing facing different directions can maintain the smooth rotation of the shaft completely.