Butterflies can directly absorb heat from the sun via their wings to facilitate autonomous flight. However, how is the heat absorbed by the butterfly from sunlight stored and transmitted in the wing? The scientifc question remains unclear. Thus, in this study, we measured the thoracic temperature in the butterfly Tirumala limniace (Cramer) at different light intensities and wing opening angles, the thoracic temperature of butterflies with only one right fore wing or one right hind wing, the spectral reflectance of the wing surfaces, the thoracic temperature of butterflies with the scales removed or not in light or dark areas, and the real-time changes in heat absorption by the wing surfaces with temperature. High intensity light (600–60000 lx) allowed the butterflies to absorb more heat and 60−90° was the optimal angle for heat absorption. The heat absorption capacity was stronger in the fore wings than the hind wings. Dark areas on the wing surfaces were heat absorption areas. The dark areas in the mid-posterior near the wing base of wing cells A-Cu3 and Cu2-Cu3 on the fore wing, and wing cells 1A-Cu2, Cu1-Cu2, M3-Cu1, and R2-M1 on the hind wing were heat storage areas. Heat was transferred from the heat storage areas to the wing base through veins Cu2, Cu3, Cu, and A in the fore wing, and veins 1A, Cu2, Cu1, Cu, M1, M3, M, R2, and R in the hind wing.