Abstract: Aiming at the problems of high cutting temperature and large cutting forces in the machining of K403 cast superalloy, which lead to severe tool wear and difficulties in ensuring machining surface quality and machining accuracy, a low-temperature minimum quantity lubrication (MQL) cutting method for K403 cast superalloy is proposed. Experiments on minimum quantity lubrication cutting of K403 cast superalloy were conducted under five cooling conditions, namely liquid nitrogen (LN₂), minimum quantity lubrication (MQL), supercritical carbon dioxide (ScCO₂), ScCO₂ + MQL, and ScCO₂ + MQL + Air. The results show that the cooling strategy of ScCO₂ + MQL exhibits excellent comprehensive performance in terms of cooling efficiency and lubrication. This approach can effectively reduce surface defects on the machined surface of K403 cast superalloy, lower surface roughness Ra, decrease tool wear, and reduce cutting forces, thereby effectively improving the turning performance of K403 cast superalloy. This study provides valuable technical support for the precision cutting of K403 cast superalloy.