Pin-fin cooling is commonly used in the trailing edge area of gas turbines to enhance heat transfer and improve the structural strength of the blades. At present, researchers mainly use size or shape optimization to improve the flow heat transfer performance of traditional cylindrical pin-fin cooling. However, the optimization potential of pin-fin cooling can be more fully exploited through topology optimization methods. On the basis of the cylindrical pin-fin structure, the topology optimization method based on level set is used to improve the heat transfer and pressure loss performance of the cooling channel of the column pin-fin, and the research results show that the shape of the optimized channel spoiler element presents a tadpole-shaped structure downstream of the column pin-fin. These tadpole-shaped structures modify the flow, leading to acceleration along the flow direction and a reduction in the low-velocity wake region. Consequently, the Nusselt number (Nu) gradually increases along the flow direction. The optimized model achieves the highest heat transfer intensity with a relatively low pressure loss, resulting in the best overall thermo-hydraulic performance.