Abstract A single-crystal hollow turbine blade was taken as the typical part to estimate the interfacial heat-transfer coefficient (IHTC) during investment-casting process. The experimental scheme was followed to measure the temperature distributions during the casting process by the tungsten–rhenium (W–Re) thermocouples. Using the finite-element methodology and the measured temperatures during the casting process, the time-dependent interfacial heat-transfer coefficient was studied by inverse heat-conduction analysis. The empirical formula for the time-dependent interfacial heat-transfer coefficient can be established. The calculation results are in good agreement with the experimental results, and the accuracy of the casting numerical simulation is improved effectively.