The characteristic of pulse xenon flashlamp envelope, which made of cerium doped quartz glass, was studied experimentally under high input power, and the experimental results were analysed. The experimentation was performed under the condition that the input energy of flashlamp is sixty percent of the explosion energy. With the number of shot increasing, map cracking occurs at the surface of the electrode, and white pattern,milky white deposition and hairline cracks emerge on the inner surface wall of the envelope. The oxygen released from the quartz glass envelope changes the color of the gas under high frequency spark discharge from indigo into green. Shock wave and thermal load are the two main effects on the envelope during the discharge. The analyse results indicate that thermal load is the major reason for hairline crack occured in the inner wall of envelope and shock wave will accelarete cracking of envelope.