By using OMA-2 system (Optical Multichannel Analyzer), the spectral distribution and UV spectral effeeiency in 2200 to 8800 A region of a flash-lamp with a pulse width (FWHM) of about 3 /LIS have been measured. Only four pulses are required for making each measurement.The influence of variation of discharge voltage and the gas pressure of the flash-lamp on its spectral distribution has been investigated. The UV spectral efficiency is increased from 13% to 17% with the increasing of discharge voltage and gas pressure. The total UV emission energy also increases appreciably.