Abstract: The portable micro-X-ray fluorescence spectrometer was developed and its hardware, software and performances were analyzed in this paper. In this spectrometer, the distance between the irradiation spot of sample and exit of polycapillary X-ray optics was automatically controlled by laser displacement sensor (LDS). By this way, the sizes of focused X-ray spot keep constants in order to decrease the errors caused by irregular or curving surface of archaeological object. In order to test the feasibilities of this spectrometer, the elemental mappings on the irregular colored glaze of a piece of ancient porcelain whose height difference is nearly 5 mm were scanned by portable micro-X-ray fluorescence spectrometer. The experimental results show that LDS can effectively reduce measurement errors caused by irregularity or curvature of sample surface. In the same time, an area with a size of 4 mm×4 mm on the RMB 5 Jiao coin’s surface was measured by the spectrometer, and the distributions of Cu, Sn and their alloys’ crystal phases were got after data processing. It indicates that this spectrometer not only can do micro energy dispersion X-ray fluorescence analysis (μ-EDXRF), but also can do micro energy dispersion X-ray diffraction analysis (μ-EDXRD).