To meet the diagnostic requirements of physical experiments in the implosion compression and arrest stage, an optical design of Wolter-Ⅲ X-ray microscope with short focal length and high magnification satisfying the Abbe sine condition was proposed. This paper introduces, the structural characteristics and design method of Wolter type Ⅲ microscope in detail. Compared with Wolter typeⅠmicroscope, the focal length of the system can be reduced by moving the main plane to the direction of the object point, so as to obtain a larger magnification. The image quality matching between microscope and detector is realized to improve the spatial resolution of diagnostic system. It can be obtained by ray tracing that the spatial resolution is better than 3 μm in the field of view of ± 190 μm. The resolution is better than 5 μm in the field of view of ±240 μm. In the field of view of ±300 μm, the resolution is better than 8 μm. The geometric solid light angle is about 5×10^-6 sr.