The 4716MA0 Ni-base superalloy (4716MA0) was melted by vacuum induction, and Ultrasonic Treatment (UT) was added to the solidification process to obtain uniform microstructure, and improve its mechanical properties. The microstructure of 4716MA0 under different UT times was characterized by SEM, EDS, EPMA, and EBSD, and the tensile test of the sample was carried out. The results showed that with the increase in UT time, the columnar dendrites gradually transformed into equiaxed crystals, the grain misorientation increases, and the high-angle grain boundaries (HAGBs) increased. The segregation behavior of elements gradually weakened, and the segregation area gradually decreased. The areas of carbides and γ/γ' eutectic gradually decreased, the proportion of carbides in GB gradually increased, and the carbides dispersed in the GB, which improves the tensile properties of 4716MA0.