Abstract: The grain size in the turbine core of K418b superalloy is so large that the mechanical properties are not strong enough, which is easy to cause damage. Its effects on the microstructure and performance of K418b alloy were discussed by the composite method of controlling pouring temperature and mechanical vibration. The results show that the grains in the core of the turbine are refined, the mechanical properties of the core of the turbine are significantly improved by controlling the pouring temperature at 1360 ℃, and the mechanical vibration with frequency of 80 Hz and amplitude of 1.0 mm after pouring, and the design requirements of the products are met.