Abstract: Specimen was designed to simulate the weld of submarine pressure hull according to its welding procedurne, and the explosive procedune was designed to relieve welding residual stress of the specimen according to the basic principle and the experience of welding residual stress relieving by using explosive method.Experimental research on welding residual stress relieving of steel 921A was carried out. The results show that explosive relieving both on one side and on double sides can regulate and relieve residual stress. The distribution of the residual stress is more regular, and the relieving effect of contact explosion is better than non-contact explosion, explosion wave is better than the bouncing rarefaction wave. Explosion on double sides is better than on one side.