To accurately measure the buckling deformation of high-strength steel sheets under high-temperature welding conditions, a visual measurement technique for the full-field dynamic welding deformation of high-strength steel sheets was proposed based on digital image processing technology, the stereo vision principle, and the digital image correlation method. This process was applied to a welding image based on the study of the high-precision matching method of a plaque image. For the discoloration or shedding of the speckle texture caused by high-temperature welding, high-temperature paint and high-temperature glue were mixed and coated to obtain a low-cost, high-stability speckle texture. The measurement of the back side of the thin plate and the addition of a filter set in front of the camera lens suppressed the interference of glare, sparks, and smoke during the soldering process. Gaussian smooth digital image processing technology was used to find the optimal filtering parameters and apply them to the welding image, which improved the image matching success rate and matching accuracy under the premise of ensuring measurement accuracy. The experimental results show that the proposed method can effectively reduce the mean error, root mean square error, and Z-direction static mean error of the welded image. The maximum value of the mean error is 78.6% and the mean square error is 47.7%. The Z-direction static mean error was 37.9%. The method and system of this study can meet the full-field strain measurement requirements of the buckling deformation of thin plates under high-temperature welding conditions. The speckle texture is stable and the speckle image matching success rate is high, demonstrating adequate stability. This technique is an effective way to detect the whole field dynamic welding deformation of thin plates.