Abstract: Provided is a method for measuring residual stress in a thin plate. The method includes: S1: prearranging and cutting a plurality of fins, computing x-direction strain ?i0 and x-direction residual stress ?i0 in the length direction of the thin plate borne by each fin, and obtaining distribution of x-direction residual stress in the width direction of the thin plate according to all ?i0; S2: repeatedly cutting the fixed ends in a thickness direction of the thin plate, computing a total cutting depth Zij and x-direction residual stress ?ij of each fin after each cutting, and obtaining distribution of x-direction residual stress in the thickness direction of the thin plate borne by an ith fin according to all ?ij; and S3: computing distribution ?x, ?x=?i0+?ij, of x-direction residual stress on a yz cross section of the thin plate according to ?i0 obtained in S1 and corresponding ?ij in S2.