The invention discloses a method and apparatus for CT image reconstruction. The method for CT image reconstruction of the present invention comprises the steps of: selecting projection data of the same height on a curve having a curvature approximate to that of the scanning circular orbit; implementing weighting processing on the selected projection data; filtering the weighting processed projection data along the horizontal direction; implementing three-dimensional back projection on the filtered projection data along the direction of ray. The apparatus for CT image reconstruction of the present invention comprises a rebinning unit, a weighting unit, a filtering unit and a back projection unit. Employment of the technical solution of the invention can effectively eliminate cone beam artifact under a large cone angle.