Herein, the effect of extreme ultraviolet (EUV) source parameters, such as discharge frequency, electric pulse energy, and buffer gas pressure, on the focused beam performance of the EUV radiation-damage-test system was studied. Results show that the focal depth of the EUV radiation-damage-test system was approximately ±1.5 mm. Although the discharge frequency has no significant effect on them, the focal spot size and single pulse energy increased with increasing electric pulse energy. Under typical working conditions, the range of focal spot size was 0.79-1.44 mm and that of single pulse energy was 112.09-436.06 μJ. The highest single pulse energy and single pulse energy density were 436.06 μJ and 31.53 mJ/cm 2, respectively, with 200-Hz source discharge frequency and 5.0-J electric pulse energy. Moreover, the highest power density of 32.87 W/cm 2 can be achieved with 1500-Hz source discharge frequency and 4.6-J electric pulse energy. The optimal buffer gas pressure (Ar) was 1-2 Pa, and the corresponding single pulse energy of focused beam is the best. This study can provide guidance for the optimization and setting of the system parameters for the study of EUV radiation damage.