The invention discloses a lossless method for estimating the volume residual stress of an annular welding structure. The method comprises the following steps: carrying out the finite element numericalsimulation analysis based on ANSYS, and obtaining the deformation distribution and surface residual stress distribution of a finite element model; conducting deformation testing to obtain deformationdistribution of the welding joint, and residual stress testing is conducted to obtain surface residual stress distribution of the welding joint; checking the finite element numerical model by adopting the actual test results of the surface residual stress distribution and the deformation distribution, and outputting the finite element model conforming to the actual test; and estimating the welding residual stress condition of the whole joint by adopting the checked finite element model. Based on the method, the volume residual stress level and state of the annular welding structure can be mastered easily, research results have guiding significance on improvement of the welding process of the structure. The input is provided for structural safety and reliability analysis and integrity evaluation.