Abstract: A customized microscope objective for near ultraviolet (UV)-visible spectrum was designed, which was used to observe the image of nuclear fusion irradiated by laser. The operation wavelength was 300 nm~500 nm, the magnification was 10 and the numerical aperture(NA) was 0.3. The transmissionmode structure was established in the microscope objective, by theoretical calculation with PW method and optimization with CODE-V, the apochromatism was achieved. Thus, the problems such as difficult aberration correction and low efficiency of optical system, resulted from the few kinds of UV optical materials and low refractive index, could be solved.