By utilizing the convenient physical vapor deposition procedure, a simple and low-cost synthesis route is developed to fabricate high-quality orthorhombic MoO3 crystals with single crystallinity and significant size (bigger than 10 mm x 10 mm(2)). A combined characterization techniques of atomic force microscopy, X-ray photoelectron spectroscopy, synchrotron-based X-ray diffraction and Raman spectroscopy confirm the high quality of alpha-MoO(3 )crystal from the point view of both electronic and physical structures. Compared to previous reports in literature, we demonstrate herein a rather simplified one-step approach with only the MoO3 powder needed. In the end, corresponding electrochromic performance has also been tested which reveals high transmittance and remarkable optical properties which may broadens the potential applications of MoO3 single crystal in nanosensors, nanoelectronics and so on.