Vanadium dioxide (VO₂) has attracted many attention of researchers since it was discovered in 1959 to have the reversible phase transition from metal to insulator. Before and after the phase transition, its optical, electrical and thermal properties change dramatically. Therefore, vanadium dioxide is widely used in the fields of thermal light control, infrared and optical protection camouflage, ion batteries and chemical sensors. In order to enable domestic researchers to have a more comprehensive and in-depth understanding of this interesting material with broad application prospects, this paper reviews the latest progress of vanadium dioxide film preparation technology in the past five years and its applications in different hot areas.First, we introduce the structure and phase transition mechanism of VO₂. When the temperature exceeds 68℃, VO₂ will undergo a phase transition from insulator to metal, and its crystal structure will change from monoclinic insulator to rutile metal structure. At the same time, because the crystal structure of vanadium dioxide changes after phase transformation, its corresponding energy band structure also changes. Because the crystal structure and energy band structure of VO₂ change suddenly before and after the phase transition, people devote themselves to exploring the physical mechanism of its phase transition. Up to now, there have been many research on the VO₂ phase transition mechanism, and also various research methods and devices, but there is no accurate and unified statement. In this paper, we focus on three mainstream explanations of phase transition mechanisms: the first is electron-electron correlation mechanism, i.e. electron correlation driven Mott transition; The second is the electron phonon interaction mechanism, i.e. crystal structure driven Peierls transition. The third is that electron correlation and crystal structure jointly drive VO₂ phase transition, and the supporting evidence is summarized. In addition, the phase transition characteristics of vanadium dioxide films are closely related to the preparation technology and process parameters.In the second part of this paper, many new technologies for preparing VO₂ thin films, such as high-energy pulsed magnetron sputtering, atomic layer deposition, ink-jet printing, spray pyrolysis and laser direct writing, are introduced in detail, and the advantages and disadvantages of each technology are briefly described. This part provides ideas for researchers on the preparation of materials at the initial stage of experimental design.In performance evaluation, this parameter thermal hysteresis width ΔH reflects the excellent degree of phase transition characteristics of VO₂ thin films ΔH will attenuate the phase transition behavior, reduce the working efficiency of the uncooled detector, and also reduce the sensitivity of the near-infrared optical response to temperature, thus reducing ΔH is of great significance for the wide application of VO₂ thin films in optoelectronic devices. The third part of this paper focuses on the regulating of the thermal hysteresis width ΔH. Many factors, such as stress, doping and defects, are analyzed. The stress factor is mainly reflected in the selection of substrate materials when preparing films. Different substrates will produce films with different orientations, and different orientations will show different properties. Both doping and oxygen defects change the phase transition properties of the materials by distorting the lattice of the materials in the films.The performance of materials determines the width of their application prospects. VO₂ suddenly changes optical, electrical and other properties before and after phase transition, so it is widely used in optoelectronic devices. In recent years, the combination of VO₂ thin films and two-dimensional super surface structures is also a hot direction of application. In this paper, we mainly introduce the application of VO2 thin films in the fields of modified smart windows, terahertz modulators, ultrafast optical switches, electrode materials and various sensors. This part can provide inspiration for researchers to explore new applications of VO₂ materials.Finally, the problems and prospects faced by the development of VO₂ thin films are predicted and evaluated. 1) How to prepare high-purity VO₂ thin films. 2) How to reduce the phase transition temperature without reducing the phase transition performance. The solution of these two problems can contribute to the perfect application of VO₂ materials in military, laser, and other integrated equipment systems. We sincerely hope that this paper will contribute to the development of new active materials and devices in the field of optoelectronics.