Abstract: Titanium sheet has obvious orthogonal anisotropy and biaxial strengthening effect.Based on the biaxial strength theory, the formula for the welding residual stresses existed in the titanium pressure vessel were derived and the computation and analysises were carried out according to the experimental data.The result indicates that the longitudinal and surrounding residual stresses in longitudinal weld of the welding titanium vessel are greater 50% than the titanium sheet' s yield strength.Moreover, the longitudinal and surrounding residual stresses in surrounding weld are extremely non-uniform.The numerical results show awide difference, and the simulated values of some points are even minus values.Compared the titanium pressure vessel' s experimental welding stresses with the calculated welding stresses, it is found that the most important surrounding stresses are basically consistent, and the greatest difference is less than 15%, which indicates that the computational method conforms with the real situation existed in titanium pressing pressure vessel.