Author improved the plane elastric-plastic finite element program NCAP-2Dused considerably widely in China The improvement includes following main aspects:linearalgebracic equation system was solved with wavefront method,a new increamental algorithmof accelerated iterative convergence was proposed and load computiom module which cantreat various loads was developed. Author performed calculation analysis for a actual projectby means of the improved plane elastic-plastic finite element program NCAPL. Its result isbasically identical with field actual situation. It indicates that the improved program is effec-tive.