An aluminous flat plate heat pipe prototype was manufactured and a test device was built for the prototype. The properties of the prototype were experimentally investigated by using the test device. The experimental results showed that the heat pipe had quick response to temperature and could realize temperature equilibrium rapidly. For the power of 200 W, the temperature differences on cooling surface and heating surface were only 0.87℃ and 1.37℃ respectively. With the increase of heat flux, the advantages of temperature evenness of the heat pipe became more evident. Its thermal resistance was only 0.100℃/W. This heat pipe prototype had excellent starting performance, temperature evenness and heat transfer performance.