Abstract: A method of nondestructive noncontact tightness testing of inner structure of articles based on gas discharge visualization includes the steps of providing a film for imaging on a dielectric plate and an electrode, the dielectric plate disposed on the electrode, and polarizing the dielectric plate by applying a series of high voltages pulses across the dielectric to provide a preliminary polarized dielectric plate. After the polarizing step, an article to be tested which has a multi-layer casing including an outer metallic layer is arranged on the film. The article is then subjected to a high voltage pulsed electric field by applying a high voltage electrical pulse between the electrode and the outer metallic layer and the electrode, wherein the pulsed electric field is combined with an electric field associated with the preliminary polarized dielectric plate triggers a gas discharge process. An image of the film is obtained on the film of an inner structure of the article based on the gas discharge process.