The discovery of ordered ��' phase in Co-Al-W based superalloys opens up a pathway for the development of novel Cobalt-based superalloys. ��' phase from binary compounds was calculated by first-principles methods, and the third alloying elements were also considered to stabilize and strengthen ��' phase, the ordered ��' phase with higher stability and more excellent mechanical properties was confirmed herein in novel Cobalt-based superalloys. The formation energies and lattice parameters of Co-X (X = Al, Mo, Nb, Ta, Ti, V, W) and Co-Ti-Z (Z = Al, V, Cr, Mo, Ta, W) were calculated, the results show that X = Ti and Z = Mo are better choices. The doping of Mo can stabilize the ordered L12-��' phase and improve the mechanical properties of the ��' phase when Mo occupies Ti sites. The occupying preference of alloying elements in Co3Ti lattice is analyzed, Al and Cr prefer to occupy Co sites in L12-Co3Ti lattice, while V, Mo, Ta and W prefer to occupy Ti sites. The as-cast microstructure of the five superalloys is typical dendrite with ��/��' two-phase region in the inter-dendrite. Besides, segregation phenomenon can be observed in the as-cast microstructure of the superalloys, and Ti prefers to enriched in the inter-dendrite, while other elements tend to be distributed in the dendritic arms.