The utility model provides a shield constructs machine knife dish suitable for mud stone stratum, including blade disc frame and scraper, hobbing cutter and the sword of going ahead of the rest, the full section scraper protection of blade disc frame, the scraper includes peripheral heterotypic scraper and front scraper, the hobbing cutter includes positive hobbing cutter, central hobbing cutter, peripheral hobbing cutter and inside hobbing cutter, the leading hobbing cutter 30mm of sword goes ahead of the rest, the hobbing cutter is the singleblade hobbing cutter. The shield of using this utility model constructs the machine, and to arrange the sediment in the work progress of mud stone stratum respond well, and work efficiency is high, and cutter grinder decreases fewly.