| As a kind of functional materials with great potential applications, VO2 has been applied in many devices, such as thermochromic smart windows, thermal resistor, lithium ion battery electrodes and so on. However, lack of massive production techniques is the crucial constraint on the extensive application of VO2. Hydrothermal process has been expected to facilitate large-scale synthesis of VO2 nanostructures due to its great superiority. Firstly, it is often applied under mild reaction conditions, emits low environmental pollution, and consumes low energy. Se-condly, the process has the ease of control over product′s chemical valence and crystal phase, high purity, without calcination for crystallization, thus can reduce agglomeration. Thirdly, hydrothermal process can obtain nanopowders difficult to obtain under normal conditions, and the particle size distribution is narrow, morphologies and crystal forms are controllable. In this paper, the research progress of hydrothermal synthesis of nano-VO2 and the phase transformation mechanism are introduced. The hydrothermal synthesis method, phase transition and growth mechanism of VO2 with different morphologies and phases in the hydrothermal process are emphatically introduced. Finally, some problems and challenges regarding to the hydrothermal preparation of nano-VO2 are also pointed out, and the future development direction are put in prospect.