Herein, the cause and change of micropores, the cause of the incipient melting structures, and the increase of the maximum homogenization temperature of a nickel‐based single crystal (SC) superalloy during homogenization are researched. The results show that the micropores are generated because of unbalanced diffusion during homogenization and form incipient melting structures at high temperature because of the lack of rhenium (Re) and tungsten (W). With the diffusion of Re and W, the porosity is decreased from 0.169% to 0.06% and cannot be further decreased because of the existence of shrinkage pores, the maximum homogenization temperature is increased to more than 1350 °C, and the rupture life at 1100 °C/150 MPa is improved to 217 h.