In order to solve the problem of speckle image quality degradation caused by non-uniform lighting in the scene, which affects the testing accuracy of digital image correlation, the multi-scale bilateral filtering Retinex algorithm was used to perform optical correction on speckle images, achieving high-precision optical measurement of displacement and stress fields in non-uniform lighting scenes. Experiments were conducted to simulate sub-pixel displacement of speckle images and compared them with existing image optical correction algorithms, the corresponding speckle image displacement mean error, standard deviation, and quality evaluation index data were respectively obtained. The results show that the proposed algorithm has a good correction effect on non-uniform illumination speckle images, and the problems of image boundary blur and local overcorrection can be solved. The average grayscale gradient of the corrected speckle image increased from 12.986 to 14.574, and the displacement standard deviation decreased from 0.0443 to 0.0335. This method can effectively enhance the quality of speckle, ensure the testing accuracy and stability of digital image correlation methods in scenarios with uneven lighting, improve the testing accuracy of digital image correlation methods in complex lighting scenarios, and provide reference for non-contact measurement of lighting mutations in actual environments.