Micro torsion angle measuring method based on infrared thermal imaging technology

The invention discloses a micro torsion angle measuring method based on an infrared thermal imaging technology, which comprises the following steps of: firstly, installing an infrared thermal imager, and enabling a lens of the infrared thermal imager to be vertical to the axis of a metal sample; respectively making two mark points at the outermost ends of the two ends of the metal sample in a manner of painting pigment, wherein the two mark points at each end form an angle of 180 degrees; the metal sample is subjected to torsional deformation under the action of external torsion, and an infrared thermal imager is used for collecting infrared images to obtain the overall contour of the metal sample; distinguishing the positions of the mark points in the infrared image; and finally, acquiring an image of the angle change of the marking line under the time sequence, extracting the motion trail of the marking point, and measuring the torsion angle by taking the edge contour line of the metal sample as a reference