Grating torque transducer

Disclosed is a grating torsion sensor which comprises a shell and a foundation, wherein in the center of the shell is equipped with a horizontal rotary axle, of which two ends stand out the shell, one end is connected with a power source and the other end is connected with a load to be tested; the shell is fixed on the foundation, in which is equipped with an asynchronism motor and a sensing component, the rotor of the asynchronism motor is movably joint on the rotary; the sensing component includes two pairs of grating groups and two pairs of photoelectric transmitting receiving device; the grating groups near to the two sides of the shell and includes a pair of matched inner and outer grating slices, wherein the outer grating slice is fixed on the rotary, and the inner grating slice is at the inner side of the outer grating slice and fixed with the rotor of the asynchronism motor; the photoelectric transmitting receiving device includes a photoelectric transmitting tube and a photoelectric receiving tube, which are separated by the grating groups, and their leading-out ends are connected with a testing instrument.