Abstract: A brief analysis was conducted on the error characteristics of mechanical torque wrenches under high and low temperature alternating environments, and a high and low temperature alternating error compensation model was established. To address the metrological drift of mechanical torque wrenches under high and low temperature alternating environments, an error characteristic study was conducted on an STW-200. Based on this, a temperature-torque coupled compensation model was established. Through least squares parameter identification and the introduction of a quadratic temperature term optimization, the post-compensation error peak-to-peak value was reduced to ±0.25%. Engineering verification indicated that the device improved the torque qualification rate of the automobile chassis assembly line by over 10%, while maintaining a takt time of ≤2.5 s.