Rhenium trioxide (ReO3) has great application potential in solid-state batteries, electrochromic and liquid crystal devices owing to its relatively simple structure and high conductivity. It is also an important material for the fundamental studies in surface science, analytical chemistry, biophysics etc. However, the complicated phase diagram of rhenium oxides brings critical challenges to the synthesis of single-phased cubic ReO3 materials. In this paper, we synthesize ReO3 bulk by direct sintering of the pressed chips of ReO3 powders under the ambient pressure. With the characterizations of X-ray diffraction (XRD), electric transport and scanning electron microscope (SEM), we optimize the sintering temperature and time, and obtain the ReO3 materials in monophase of the cubic structure, with high crystalline homogeneity and high density. Preliminary growth experiments demonstrate that the obtained ReO3 can be used as the target in pulsed laser deposition technology, promising for future researches on the high-quality ReO3 films.