High-temperature insulation materials are critical components of thermal protection systems for hypersonic vehicles, gas turbines, and other advanced technologies. In these contexts, the assessment of thermal insulation performance through the measurement of thermal conductivity is essential. This study measures the effective thermal conductivity of high-dimensional S blanket, aluminum silicate cotton needle felt, and nano-aerogel blanket insulation fibers using the heat flux meter method under two environmental conditions: dry and 60% relative humidity. The experiments covered hot surface temperatures ranging from 50°C to 550°C, encompassing 90 distinct operational conditions. The results elucidate the variation patterns of both the effective and true thermal conductivity of these materials. The findings indicate that (1) fitting models for the effective thermal conductivity of the high-dimensional S blanket, aluminum silicate cotton needle felt, and nanoaerogel blanket provided accurate predictions; (2) Humidity significantly affected both the effective and true thermal conductivity at high temperatures for the high-dimensional S blanket and aluminum silicate cotton needle felt, but had a relatively minor impact on the nano-aerogel blanket.; (3) Incorporating true thermal conductivity allowed for accurate predictions of material performance in 42 experimental conditions, with strong agreement between calculated values and experimental data.