Argon gas quenching is an essential method for the vacuum heat treatment of single crystal turbine blades. A systematic investigation was carried out on three kinds of argon gas pressures were applied and the effect of solution cooling rates (4.8, 5.8 and 8.0 ℃/s) on the microstructure and properties of a third-generation single crystal superalloy and double-wall ultra-cooling turbine blade. The results show that the cuboidal forms of γ′ phases are well-developed under three kinds of solution cooling rates. Moreover, the solution cooling rates have a relatively limited effect on the cuboidal degree of the γ′ phases. There are only a few residual γ-γ′ eutectic in the aerofoil and tenon sections after the full heat treatment. The average sizes of the γ′ phases decrease, as the solution cooling rates increase, and the size distributions of the γ′ phases follow the normal distribution. As the solution cooling rate increases, the size dispersion degrees of the γ′ phases tend to be smaller. The solution cooling rates have a little effect on the yield strength and ultimate tensile strength of the alloy at 760 ℃, while the stress rupture life of the alloy at 1100 ℃/137 MPa shows a downward trend, as the solution cooling rate increases. The fracture surfaces of the alloy at 760 ℃ are all characterized by quasi-cleavage features. The fracture surfaces of the alloy at 1100 ℃/137 MPa are all characterized by dimple features. This finding can significantly contribute to obtain the optimal matching of microstructure and mechanical properties of the third-generation single crystal turbine blade.