The turbine disk is a crucial heat-resistant component of aeronautical engines. An investigation into the similarities and differences in the microstructure and mechanical properties of superalloys fabricated using powder metallurgy and conventional casting and wrought methods could provide a theoretical framework for ensuring the production and operational reliability of turbine disks that are difficult to deform. GH4720Li (Udimet720Li) alloy is a commonly used nickel-based superalloy reinforced through precipitation. The volume fraction of γ' precipitation in GH4720Li alloy is 45%. It is mainly used to make compressor and turbine disks for use at 650-750 ^oC, as well as turbine disks for use at 900 ^oC in a short time. The mechanical properties of the GH4720Li alloy are closely associated with its microstructure. The mechanical properties of the alloy, including hardness, yield strength, and tensile strength, are influenced by factors such as grain size and orientation, distribution of the γ′ phase, presence of twins, and arrangement of grain boundaries. To investigate the similarities and differences of the microstructure and mechanical properties between powder alloy (FGH4720Li alloy) and wrought alloy (GH4720Li alloy), which were prepared by powder metallurgy and traditional cast and wrought processes, the microstructure characteristics of FGH4720Li alloy and GH4720Li alloy were observed and analyzed by SEM, TEM, and EBSD (FGH4720Li alloy). The mechanical properties of both alloys were studied via Vickers hardness and high-temperature tensile tests. Furthermore, the relationship between the microstructure and mechanical properties of both alloys was thoroughly discussed. Results show that the distribution characteristics of dislocation, twin substructure morphology, grain orientation concentration, and twin boundary in both alloys are similar. Wide twins (0.5-1 μm) and some narrow twins (< 100 nm) were observed in both two alloys, and the type of twin boundary is primarily Σ3. No obvious preferred orientation was noticed in both alloys. The difference is that the size of γ{}_{\mathrm{I}}^{\text{'}} phase in the GH4720Li alloy (1.92-2.41 μm) is larger than that in the FGH4720Li alloy (1.41-1.51 μm), whereas the size of γ{}_{\mathrm{I}\mathrm{I}}^{\text{'}}phase in the powder FGH4720Li alloy (66.24-73.15 nm) is higher than that in the GH4720Li alloy (64.74-72.29 nm); additionally, a petal-like γ{}_{\mathrm{I}\mathrm{I}}^{\text{'}} was observed in the FGH4720Li alloy. The proportion of grain size between 12 and 24 μm in the GH4720Li alloy is higher than that in the FGH4720Li alloy, and the microstructure of the GH4720Li alloy contains some coarse grains (32-36 μm). The percentage of high angle grain boundaries in both alloys is higher than 83%. However, FGH4720Li alloy has a higher fraction of low angle grain boundaries than GH4720Li alloy. Additionally, FGH4720Li alloy exhibits a more pronounced variation in intracrystalline orientation. Furthermore, FGH4720Li alloy with small average grain size exhibits higher hardness, yield strength, and ultimate tensile strength than GH4720Li alloy.