In order to improve the heat transfer characteristics of plane flow casting cooling roll and improve the transverse thickness uniformity of Fe-Si-Be amorphous strip, a numerical model of axial heat transfer channel is established. Based on the analysis of the current axial flow and heat transfer characteristics of cooling roller, a design method of spherical heat transfer channel is proposed. Based on the field synergy theory, the spherical channel is optimized and verified by experiments. The results show that the heat transfer efficiency of the cooling water in the channel decreases gradually along the water flow direction, and the heat transfer mainly occurs near the inner wall of the cooling roller. The temperature in the middle of the existing cooling roller outer wall is much higher than that at both ends, and the axial temperature difference is obvious. The spherical channel can strengthen the heat transfer in the middle of the cooling roller, reduce the temperature, thermal deformation and axial deformation difference of the outer wall, and significantly improve the transverse thickness of the amorphous thin strip with the decrease of the radius of the sphere. The heat transfer in the middle of the channel increases obviously, but the flow resistance also increases sharply. There is an optimal channel optimization radius based on the comprehensive flow resistance and heat transfer characteristics conditions.