A preconditioning process encompassed vacuum baking and burnin with ultraviolet radiation. An equipment of preconditioning of microchannel plate was designed which could provide vacuum environment (10－5 Pa at least) as well as heating elements. The heating elements were controlled to reach 350℃ and then the vacuum chamber was sustained 350℃ for 18 hours in the procedure of bakeout. The burnin procedure illuminating with ultraviolet radiation (253.7 nm) from a deuterium lamp was achieved when 0.06 Coulomb cm－2 was extracted from the MCP stack output. After the preconditioning the image spatial resolution reached to 125 μm, the background events rate dropped to be 0.53 counts/s·cm2 from 27.09 counts/s·cm2, the pluse height distribution curve closed to Gauss distribution and turned to be more narrow.