The depth of the grooves in the internal structure of the casting is too large, it is difficult to control the slurry, and the drying is difficult. Casting floating core and blade deformation are prone to occur, which brings great difficulty to the dipping. sanding and drying of the shell.A special process is adopted to solve the above problems, and at the same time, the casting temperature and casting speed are strictly controlled to ensure that each blade is fully filled and dense, and meets the product quality requirements.