Abstract: The digital result of surface displacement deformation field under uniform thermal load of chip solder joint (no more than  0.8 mm) was successfully got by digital image correlation method. The system combined the long distance microscopic observation and image acquisition system, thermostats controllable heating and lighting systems and other hardwares, and it made the digital image correlation method possible to proceed research in micro field. At the same time, finite element method was simulated with the same boundary conditions and the caculated results showed that datas obtained by the two methods were in good agreement. Testing results showed that the digital image correlation method and the designed testing system was in good accuracy and stability in micro deformation measurement.