Abstract: An electronbeam Teslatransformer accelerator is described. It consists of the primary storage energy system, Tesla transformer, oil Blumlein pulse form line, and the vacuum diode. The experiments of initial stage showed that diode voltage rises up to about 500kV with an input of 20kV and the maximum electronbean current is about 9kA, the pulse width is about 50ns. This device can operate stably and be set up easily．