For plate steel castings, the foundry technology was designed according to the dynamic directional solidification of proportional solidification theory. Adopting chilling process for the thick and large plane, it may cause the casting basically even cooling. Using self-feeding shrinkage in solidification achieved the dynamic directional feeding of molten steel, and the casting was poured and congealing at the same time. The shrinkage of finally congealing part was fed by small riser. Adopting this foundry technology, the large plane downwards avoided appearing the defects such as sand buckle, slag, pinhole porosity, and pore, etc.; the process yield was greatly increased with this foundry technology, too.