Abstract:This paper presents a study of oriented carrier-wave in photo-elasticity mechanics and the distributing of luminous intensity. At the same time the distributing rule of stripe of oriented carrierwave of photo-elasticity has also been analyzed, presenting a new method of photo-elasticity with oriented carrier-wave for testing direction of principal stress. According to this method, an apparatus of oriented carrier-wave of photo-elasticity was designed and fabricated and, then put into traditional photo-elastic equipment, so the stress trajectories map was obtained including the direction of principal stress, The number of photo-elastic stress patters and stress trajectories was obtained with image processing methods and the precision of photo-elasticity method was improved a lot,paving a way for the application of optical engineering in the photo-elasticity mechanics field.