Background <p>Strain gauges used for strain measurement in mechanical testing are pasted manually, resulting in discrepancies between the actual measurement direction and the theoretical measurement direction. These deviations lead to measurement errors, which are more pronounced in high strain gradient regions such as openings, reinforcements, and notches. The actual direction of the strain gauge measurement cannot be determined directly.</p> Objective <p>This study aims to accurately determine the actual measurement direction of strain gauges using a non-contact method.</p> Methods <p>A non-contact method for precise strain gauge orientation is proposed. By combining solder joints and boundary features, high-precision strain gauge recognition and pixel acquisition for orientation determination are achieved. A binocular vision method is employed to locate the coordinates of the image pixels, thereby determining the measurement direction of the strain gauges.</p> Results <p>The proposed method has been validated through an experiment on a cylindrical structure commonly used in aerospace engineering. The results showed that the angular errors between the values obtained by this method and the standard values ranged from 3.39° to 5.6°.</p> Conclusion <p>The proposed precise orientation method for strain gauges, based on solder joints and boundaries, can determine the high-precision measurement directions of strain gauges.</p>