Having analyzed the features shown by air breakdown an injulating outer hard, and that cause solid medium to produce a creeping overflash, the paper presents points for a vacuum switch outer hard to be designed, namely that the minimum height of the outer hard is determined by an impulse voltage, however the creeping distance is determined by a working voltage and environmental conditions.

The paper establishes a complete set of the vacuum degree calibration system directing against some points, and also proposes the calibration curves after actual measurements, which indicates that the vacuum degree of the vacuum switch responds to the current of the electric discharge.

Glass ceramics which is suitable for making insulating enclosure of the vacuum interrupter,the procedure finishing glass ceramics molding and with the metal sealing at the same time, and the treatment procedure of the metal are researched emphasisly in this thesis.