Advanced aeroengines and other high-temperature alloy components are constantly evolving towards more complex structures and thin-walled lightweight designs, potentially resulting in issues such as challenging casting, non-uniform microstructures, and solidification defects. These issues pose new challenges for precision casting techniques and process control in the manufacturing of such castings. In this regard, the filling ability, shrinkage, microstructure and mechanical properties of K4169 castings with thin walls and variable cross-sections were compared between conventional casting and thermally controlled solidification methods. The results show that under conventional casting, the filling percentage of the thin-walled part casting is only 26%, and porosity is found in the variable cross-section part. Thermally controlled solidification at a pouring temperature of 1 360 ℃ can increase the filling percentage by 226%, significantly reducing the shrinkage in the casting. A fine grain structure with an average grain size of 624 μm and secondary dendrite spacing of 116 μm is obtained during casting, where the amount of Laves phase is relatively small. Moreover, thermally controlled solidification at a low pouring temperature effectively achieves refinement of the solidification microstructure and defect control, the tensile strength of the alloy increases by 7%, and the elongation increases from 6% to 8% at 700 ℃.