As an advanced high-performance light alloy material with exceptional ductility, electrical conductivity, and superior physical-mechanical properties, 7075 aluminum alloy has found extensive applications in critical fields such as new energy vehicles, aerospace, and shipbuilding, emerging as an ideal material to meet the stringent performance requirements of high-end manufacturing. Acknowledging the current gap in systematic research on the number of teeth in milling cutters, this study employs 7075 aluminum alloy as the workpiece material and utilizes ANSYS finite element analysis software to establish digital models of two-tooth, three-tooth, and four-tooth cylindrical milling cutters, followed by transient thermal analysis. Through parameter optimization and solution calculation, the results demonstrate that the four-tooth milling cutter exhibits significantly lower directional heat flux compared to its two-tooth and three-tooth counterparts, albeit with relatively higher outer wall temperature. Concurrently, the four-tooth milling cutter demonstrates notably smaller total deformation, along with lower instantaneous and average milling forces. These findings provide a substantial foundation for optimizing the structural design of milling cutters and enhancing their performance capabilities, offering critical insights for advancing machining technology in high-precision manufacturing domains.