A new high power, short duration time XeCl laser is realized in the proportion of HCl:Xe:He=0.12%:1%:98.88%, in order to prepare microstructure of quantum effect, molecular beam epitaxy, depositing film and analysis of output pulse profiles. Based on the analysis of gain coefficient and saturated state, with the increase of gas pressure and discharge voltage, the short duration time of laser pulse is obtained. The working pulse of XeCl laser is 18.65 ns. Calculated result indicated not only that the structure and the kinetics velocity equation of laser are suitable, but also which the duration time of pulse is shorter under unsatured process and is rising at satured state with growth of the pumped power. The new XeCl laser has the advantage of smaller heat affected zones, which has acted on the target material to produce the vapor plasma plume, carrying out more accurate nano-crystalline structures.