VO 2 (M) shows a reversible first-order metal–insulator transition to metallic rutile phase VO 2 (R) at 68°C. The large-scale and low-cost synthesis of VO 2 (M) are challenge for materials scientists. In this paper, belt-like W-doped VO 2 (M) with rectangular cross sections was successfully synthesized using peroxovanadium (V) complexes as the vanadium precursor and ethanol as the reducing agent by a facile one-step hydrothermal approach for the first time. The samples were separately characterized by XRD, EDS, XPS, XRF, SEM, DSC and variable-temperature FTIR. Some parameters, such as the quantity of the dopants, reaction temperature, reaction time, kinds of dopants and volume of ethanol, were briefly discussed to synthesize W-doped VO 2 (M) solid solution. It is found that doped atoms can be successfully doped into the crystal lattice of VO 2 matrix, and the morphologies of the samples are described as highly faceted micro- and nano-belts structures with rectangular cross sections. The formation mechanism of W-doped VO 2 (M) was discussed in detail. The phase transition temperature of W-doped VO 2 (M) can be simply tuned by changing the doping concentration of W atom within appropriate limits. The variable-temperature infrared spectra reveal that the doped VO 2 (M) has outstanding thermochromic characters and optical switching properties.