Abstract: Scattering of flexural waves by multiple cutouts and dynamic stress concentration in the thin plates were investigated in terms of the complex variable function method and multi-polar coordinates. The expressions of function approach sequences and condition boundary for the general solution to this problem were proposed by deducing the bending motion equations of the plates. It was solved as a series of infinite algebraic equations by expanding the orthogonal functions. The dynamic moment factors of the plates with three circular cutouts were numerically presented, and the influences of paces between circular cutouts and wave number on dynamic stress distribution were analyzed.