During the casting of sand-coated iron mold ductile iron crankshafts, the interfacial heat transfer coefficient(HTC) is a key parameter governing the evolution of the temperature field and solidification behavior; however, it isstrongly affected by temperature variation, interfacial air-gap formation, and changes in contact conditions, making accuratedetermination by conventional methods difficult. In this study, thermocouples were synchronously embedded inside thecasting and within the sand coating under actual production conditions to record the temperature histories throughout theentire filling and solidification process. On this basis, the HTC at the casting-sand coating and sand coating-iron moldinterfaces was inversely determined using the Optimization module in ProCAST software. The results indicate that theinterfacial HTC of the cast/sand coating exhibits a pronounced stage-dependent variation with temperature, increasing fromapproximately 315 W/(m2·K) to approximately 712.5 W/(m2·K) as the temperature increases and significantly changes inthe liquid-solid phase transformation region. When the inversely determined HTC is applied as the boundary condition inthe simulation, the calculated temperature curves show good agreement with the experimental results after 1 500 s, with theoverall deviation controlled within 5% , which is markedly better than that obtained using a constant HTC model. Theresults demonstrate that considering the temperature dependence of the HTC can effectively improve the reliability of thetemperature field simulation for the sand-coated iron mold casting process.