Stress measurement is an important scientific and practical problem, since most structures have high level residual stresses. Welding is a key technology in the manufacture of structures and an area of peak residual stresses. The existing methods for assessing residual stresses have their positive and negative sides, but not all of them are suitable for work in the weld zone. The paper lists the features of the weld zone that limit the applicability of most methods. Among the mechanical methods for assessing residual stresses, the hole method is most suitable for working in the area of the weld. There are two versions of using the hole method: using strain gages and with optical measurement of the movement of points. It is shown that optical methods are more informative and convenient for measuring the residual stresses of the weld. The DON-5Ts3 electronic speckle interferometer, created on the basis of optical methods, has been tested for operability in laboratory and field conditions.