The invention relates to a method for strain strengthening of an austenitic stainless steel low-temperature pressure vessel. By virtue of the characteristics of water which increases volume during the solid-state phase transformation, the austenitic stainless steel low-temperature pressure vessel generates strain and further gets strengthened. During the strain strengthening, since the strains in all directions are uniform, the situation that the vessel is locally thinned and even out of work due to an excessive local deformation can be avoided. Furthermore, the strain during strain strengthening can be controlled and strain strengthening can be repeated for many times till the set strain is reached finally. More importantly, the method, compared with the Avesta mode and Ardeform mode, has the advantages of good effect, easy operation and low cost.