Abstract: Nickel-based alloys undergo complex temperature variations during actual service, where thermal fluctuations may alter elemental diffusion pathways and rates, thereby affecting microstructural homogeneity. Current long-term aging studies predominantly focus on isothermal conditions, while microstructural evolution and performance degradation under non-isothermal aging remain inadequately explored. This study aims to investigate the differences in γ′ phase evolution between isothermal and non-isothermal aging in nickel-based alloys, elucidate the influence of temperature sequences on microstructural characteristics, and establish quantitative relationships among microstructural parameters, aging time, and temperature, including equivalent time calculations. The results reveal that the growth kinetics of γ′ phase size in DZ411 alloy under both non-isothermal and isothermal aging follow an identical time-temperature function: the cube of phase diameter exhibits a linear dependence on aging time and temperature, with Feret Ratio (FR) fluctuating within comparable ranges. Furthermore, temperature sequences systematically govern γ′ phase dimensions. Microstructural observations demonstrate that sequential aging from 900℃ to 980℃ produces larger γ′ phases than the reverse sequence (980℃-900℃). Quantitative analysis confirms an average equivalent diameter (D) of 719 nm for the 900℃-980℃ sequence, exceeding 665 nm for the 980℃-900℃ sequence. Additionally, temperature sequences regulate γ′ phase morphology: rounded rectangular particles dominate in the 900℃-980℃ sequence, while near-spherical shapes prevail in the 980℃-900℃ sequence, supported by distinct FR values (1.411 vs. 1.379).