Abstract: After the problem of damping effect on the nanotubes and the substrate was settled, Carbon nanotubes (CNT) films with champion emission characteristic would be synthesized by pyrolysis of iron phthalocyanine. If the pulse electrical field was up to 30 MV/m, the emission relativity beam current was 15 kA, the corresponding current density exceeded 1 kA/cm2 and the potential emission mechanism was flashover plasma emission. When the high-current emission repetitive frequency was 10 Hz, the emission threshold electrical field was low, the current waveform was almost synchronized with the voltage waveform, the emission amplitude was equal, the extent of emission stabilization was better than that of graphite cathode. After the emission times were up to 1000 shots, the morphology of CNT was intact, the desorptions from the interface of CNT didnt occur.