Method for measuring residual stress on inner wall of small internal diameter pipeline

The invention discloses a method for measuring residual stress on an inner wall of a small internal diameter pipeline. The method of the invention comprises steps of pasting at least one strain gauge on a position where needs to measure stress, measuring an original value epsilon 1 of the strain gauge, cutting the pipeline, measuring a strain value epsilon 2 of the strain gauge after cutting, calculating the original value epsilon 1 and the strain value epsilon 2 to obtain strain epsilon 3 released by the strain gauge during the cutting, measuring pipeline residual stress sigma 4 of the position where the strain gauge is pasted after the pipeline is cut, correcting the residual stress sigma 4 through the stress sigma 3, and obtaining practical residual stress sigma 5 of the internal wall of the pipeline. The method of the invention corrects data of the residual stress on the internal wall of the small internal diameter pipeline and obtains an accurate measurement value, and is simple and practical in method.