As highly integrated and miniaturized power components rapidly develop, the extreme heat accumulation of electronic devices easily occurs, leading to an urgent demand for better thermal performance of heat dissipation devices. Besides, an efficient heat dissipation method was still essential for the development of flexible power components. Herein, a novel ultra-thin vapor chamber (UTVC) based on graphite copper-clad film with a thickness of only 0.68 mm was fabricated by a simple hot pressing process, and the composite wick structure was used as a capillarity-enhanced structure and a supporting structure for vapor flowing. The different filling liquid mass and test orientations of UTVC were both discussed. The surface temperature, temperature difference, thermal resistance, and thermal conductivity of UTVC were experimentally investigated, respectively. The UTVC could achieve a uniform surface temperature distribution (below 7.5 W), a low temperature difference (less than 2 degrees C at 6.5 W), a low thermal resistance (0.33 degrees C/ W at 6.5 W), and a high thermal conductivity (beyond 10000 W/(m center dot K)) under different orientations. Moreover, UTVC also showed wonderful flexibility, providing a potential application in the field of flexible folding. Further research will be carried out based on its flexibility.