The invention provides a torque sensor which is composed of a supporting base, stress plates, a sleeve, a thin-wall plate and resistance strain gages. The supporting base, the stress plates and the sleeve are an integrated forming structure, the sleeve is coaxially and fixedly connected with the supporting base through the tangential stress plates on two sides, the stress plates on the two sides are symmetrical with the central axis of the sleeve as the center, the outer surfaces of the stress plates on the two sides serve as tangential planes of the edges of the sleeve, and the thickness of the stress plates is between 2mm to 5mm. The resistance strain gages are attached to the inner sides and the outer sides of the stress plates, the resistance strain gages on the stress plate on one side are distributed symmetrically with the center of the stress plate as the center, and the thin-wall plate along the normal direction of the sleeve is connected between the sleeve and the supporting base. The torque sensor can be used for measuring torque of a transmission shaft directly and does not need to dismantle a measuring device, the resistance strain gages symmetrically arranged on two sides of the stress plates can eliminate influence of temperature on measuring results, and torque of an object to be measured under the static condition can be measured.