Abstract: During Tokamak plasma discharge, induced eddy currents in the vacuum vessel by PF coils and plasma have an important influence on plasma discharge. Currents are induced in PF coil and plasma by induced eddy currents in the vacuum vessel in return. In order to realize the feedback control of plasma discharge, it is necessary to calculate the induced eddy current distribution in the vacuum vessel. In this paper, by using the high speed CCD and image processing, and dividing the vacuum vessel into 40 elements, eddy current distribution was calculated with least squares algorithm, which is proved to being a desirable result.