Abstract: The as-cast microstructure of a new Ni-Co-based superalloy was observed by optical microscopy and scanning electron microscopy. The thermodynamic calculation of the alloy was carried out by JMatPro software under equilibrium and non-equilibrium solidification conditions to study the phase precipitation characteristics. The results show that the test alloy exhibited dendritic morphology and severe segregation, and mainly consisted of γ' phase, η phase, γ/γ' eutectic structure and MC carbides. Under equilibrium solidification conditions, the main precipitation phases of the test alloy were γ', η, μ, σ, carbides and borides. Increasing Ti and Al content led to an increase in γ' phase precipitation amount and precipitation temperature. The precipitation temperature and amount of η phase increased linearly with increasing Ti content. In the non-equilibrium solidification process, Ti and Mo elements were enriched in the liquid phase, while Al, Cr, Co and W elements were poor in the liquid phase.