The characteristics of superalloy powders used for the gradient integral turbine blisk by the hyper-transient solidified additive manufacturing are investigated. According to the temperature capacity of the alloy and the phase equilibrium diagram calculated by JMatPro, GH4169 and K418 alloys are selected as the disk hub and rim materials respectively, whereas DZ4125 is selected as the blade material for integral turbine blisk. The superalloy powder are prepared by vacuum induction melting and argon gas atomization (VIGA) and sieved to the particle size range of 53-105μm. The differential scanning calorimeter (DSC), field emission scanning electron microscope (FESEM), electron probe x-ray micro-analyzer (EPMA), laser diffraction particle size analyzer, dynamic image analysis system and comprehensive powder property analyzer are used to systematically characterize the phase change temperatures, microstructure, element segregation, particle size and shape, apparent density, tap density and flowability of the selected superalloy powders. The results show that the liquidus and solidus temperature range of K418 alloy is smaller than that of the GH4169 alloy. The onset precipitated temperature of γ′and MC carbides of K418 alloy is higher than that of GH4169. The precipitation temperatures of the main strengthening phases of the (GH4169+K418) hybrid composition alloy in the transition zone are between that of the GH4169 and K418 alloys. The morphology of GH4169 and K418 alloy powders is mainly spherical and nearly spherical. The surface and cross-section microstructures are mainly dendritic structure. For the selected alloy powders, the elements Ti, Nb, Zr and Mo, which is rich in the interdendritic region, exhibit strong segregation tendency, while the elements with weak segregation tendency include Ni, Cr, Fe and Al. The element segregation type of superalloy powder is similar to the cast Ni-based superalloys, however the powders possess finer and uniform microstructure than that of the cast superalloy. The particle size distribution of powders measured by laser diffraction and dynamic image analysis methods are similar. The D50 value of GH4169 is 79.1μm and 76.2μm, and the D50 of K418 is 67.8μm and 65.6μm, respectively. The dynamic image analysis result shows that the two alloys both possess good sphericity, and the SPHT mean values of GH4169 and K418 are 0.91 and 0.90, respectively. The GH4169 and K418 superalloy powders have similar apparent density, tap density and flowablity. In addition, the apparent density and tap density of the two alloy powders can reach 50% and 60% of the theoretical density of the alloy respectively. Furthermore, the GH4169 and K418 superalloy powders both have good compressibility (13.3~15.5%) and flowability of 18.5~20.4 s?(50 g)-1.