Stirring and grinding reactor and method for preparing isocyanate with same

The invention relates to a stirring and grinding integrated reactor and a method for preparing isocyanate by using the reactor. The reactor comprises a reactor shell, a first reactant feeding hole, a first reactant distributing tray, a second reactant main feeding hole, an annular second reactant distributing tray, a stirring shaft, an axial stirring paddle, a radial stirring paddle, a dynamic grinding sheet, a static grinding sheet and at least one second reactant sub feeding hole, wherein the dynamic and static grinding sheets are provided with a plurality of passage holes. Quick mixing and quick reaction between the raw materials are realized by axial and radial strong stirring and a feeding method of a strongest mixing area, and the solid reaction product is further pulverized by hole passage type quick grinding combined through multilayer dynamic and static grinding trays so as to enhance the reaction effect, improve the yield and quality of the isocyanate, reduce the using amount of a solvent and the excess ratio of phosgene, improve the yield of the device, improve the quality of the product and reduce the energy consumption.