Abstract: An experimental model, in which explosive strips were placed along the welds on single side or on double sides, was developed to simulate the circumferential weld of a large pressure-resistant cylindrical shell according to its welding craft and to explore how to relieve the circumferentially welded residual stresses. In the model experiments the two arrangements of explosive strips were both adopted to relieve the circumferentially welded residual stresses of a large pressure-resistant cylindrical shell using explosive treatment. Experimental results indicate as follows: (1) there are high welded residual stresses in the circumferential weld of the large pressure-resistant cylindrical shell; (2) single and double side treatments are both effective to regulate and relieve welded residual stresses; (3) the higher the welded residual stress, the better the relieving effect; (4) when the residual stress is higher than 0.5s, the single side treatment can relieve the residual stress m more than 40%, the double side treatment can relieve it more than 60%; (5) longitudinal stress can be relieved effectively by placing explosive strips along the weld.