Abstract: A stress measurement system was built based on digital image correlation method. The influence of speckle pattern quality on the measurement accuracy was analyzed, and the accuracy of this measurement system was verified through in-plane translation and the test of plane stress state. The results show that the measurement accuracy can be improved with the increase of the quality of speckle pattern to a certain extent. All the relative errors in the test of in-plane translation were less than 3.5%, which indicate that the system has high accuracy. When this measurement system was used to measure the welding residual stress of the chain, the results are basically the same with that from strain gauges. It's worth noting that, this stress measurement system has advantages such as simple operation and high accuracy, which can be used to measure the residual stress instead of strain gauge under certain conditions.