Abstract: The frond-end equipment of a small UAV adopts a low-profile, integrated design architecture. The electronic equipment is constrained by limited assembly space and light-weight restrictions, imposing critical demands on both physical mass and dimensions. High-density component packing drastically reduces the available volume for thermal management, prohibiting the use of bulk heat sinks. This critically limits the surface area essential for effective convective cooling, creating a paramount thermal dissipation challenge for the integrated assembly. A significant heat dissipation demands and prolonged operation require heat dissipation performance to holistically balance the mass and cost. After consideration of payload cooling efficiency and additional mass from thermal design, this study systematically enhanced thermal management through component layout optimization, bidirectional heat transfer design between the substrate and pedestal, selection of low thermal resistance materials, and heatsink structure improvement. Combined with simulation and ground-based flight simulation tests, a natural heat dissipation capacity of 160 W was achieved for the front-end payload of a small UAV in a confined space. The research has accumulated substantial test data, providing valuable insights for the thermal design of high-power electronic equipment under strict size and weight constraints.