A power-output torque detection mechanism, comprising: an axle; an input assembly, which comprises an input sleeve adapted to be driven by a power, the input sleeve being rotatably mounted on one end of the axle, an end of the input sleeve being extended to form a plurality of equidistant projecting blocks, the projecting blocks being provided with an axial ball groove formed on an outer circumferential surface thereof and extending in an axial direction; an output assembly, which comprises an output sleeve drivable by the input assembly, the output sleeve being mounted on an opposite end of the axle; and a torsion coupling assembly, which is arranged between the input sleeve and the output sleeve, the torsion coupling assembly at least comprising a rotating ring, a torque transformation ring, and a stationary ring, wherein one end of the rotating ring is fixed to the output sleeve of the output assembly, an end of the rotating ring that is opposite to the output sleeve being extended to form a plurality of equidistant chamfered blocks extendable into an interior of the torque transformation ring, the chamfered blocks being each formed with an oblique ball groove in a side thereof, the torque transformation ring being formed, in an inner circumference thereof, with a plurality of ball groove seats respectively interposable between the projecting blocks of the input sleeve and the chamfered blocks of the rotating ring, the ball groove seats being each formed with an oblique ball groove corresponding to a corresponding one of the oblique ball grooves of the rotating ring to interpose therebetween a pulley ball therebetween, the ball groove seats being each formed with an axial ball groove corresponding to a corresponding one of the axial ball grooves of the input sleeve to interpose therebetween a series of guide balls, the stationary ring being arranged, in a fixed manner, on one side of the torque transformation ring that is opposite to the rotating ring, such that the torque transformation ring is pushable and movable in the axial direction configured to press against the stationary ring, the stationary ring being provided, on at least a surface thereof, with a strain detection element, the strain detection element being adapted to connect, in a wired manner, to an external control processing unit. an axle; an input assembly, which comprises an input sleeve adapted to be driven by a power, the input sleeve being rotatably mounted on one end of the axle, an end of the input sleeve being extended to form a plurality of equidistant projecting blocks, the projecting blocks being provided with an axial ball groove formed on an outer circumferential surface thereof and extending in an axial direction; an output assembly, which comprises an output sleeve drivable by the input assembly, the output sleeve being mounted on an opposite end of the axle; and a torsion coupling assembly, which is arranged between the input sleeve and the output sleeve, the torsion coupling assembly at least comprising a rotating ring, a torque transformation ring, and a stationary ring, wherein one end of the rotating ring is fixed to the output sleeve of the output assembly, an end of the rotating ring that is opposite to the output sleeve being extended to form a plurality of equidistant chamfered blocks extendable into an interior of the torque transformation ring, the chamfered blocks being each formed with an oblique ball groove in a side thereof, the torque transformation ring being formed, in an inner circumference thereof, with a plurality of ball groove seats respectively interposable between the projecting blocks of the input sleeve and the chamfered blocks of the rotating ring, the ball groove seats being each formed with an oblique ball groove corresponding to a corresponding one of the oblique ball grooves of the rotating ring to interpose therebetween a pulley ball therebetween, the ball groove seats being each formed with an axial ball groove corresponding to a corresponding one of the axial ball grooves of the input sleeve to interpose therebetween a series of guide balls, the stationary ring being arranged, in a fixed manner, on one side of the torque transformation ring that is opposite to the rotating ring, such that the torque transformation ring is pushable and movable in the axial direction configured to press against the stationary ring, the stationary ring being provided, on at least a surface thereof, with a strain detection element, the strain detection element being adapted to connect, in a wired manner, to an external control processing unit.