A quick brake adjust knob, which is disposed on an axle of a fishing reel, includes a base disc, a passive member, an elastic member, a threaded member, an active member, and a panel disc. The passive member has a first arc slope gradually approaching the outside of the knob from a first staring end thereof to a first terminal end thereof and C-shaped with a breach where a first recess is provided. The active member has a first protrusion abutted against the first arc slope or accommodated in the first recess. The panel disc is fixed to the active member and rotatable relative to the base disc. The periphery of the panel disc is joined with the periphery of the base disc. Therefore, the quick brake adjust knob can quickly and precisely control the resistance of the fishing reel to stretch out the fishing wire.
