Abstract: A centrifugal force-controlled coupling switch mechanism including a rotary base coupled between a reversible motor shaft of a reversible motor and an output shaft, an eccentric block pivoted to the rotary base and adapted for controlling engagement between the rotary base and the output shaft, a clutch adapted for controlling the engagement between the eccentric block and the output shaft, the clutch including a clutch body having two forward locating pins forced by a spring to disengage the eccentric block from the output shaft, and three smoothly curved actuating plates equiangularly retained to the clutch body by a spring retainer and forced by a centrifugal force to expand and to push the clutch body backwards in disengaging its locating pins from the eccentric block for permitting the eccentric block to be forced into engagement with the fixed coupling block of the output shaft by the centrifugal force when, the rotary base is turned with the clutch body by the reversible motor shaft of the reversible m