Recognizing and controlling the metal-insulator transition (MIT) in VO2 transition-metal oxides is interesting for the future electronic devices. However, the effect of the electron correlation for the structure-coupled MIT in VO2 is as yet an open question. In this study, we present for the first time direct spectroscopic evidence for the charge-transfer assistance bandwidth controlled MIT (BC-MIT) in Au-VO2 nanocomposite thin films (NCTFs). A significantly enhancement of the MIT temperature (about 350 K) is realized in Au-VO2 films with Au volume ratio of 1.1 mol%. However, by further increasing Au ratios, the MIT temperature in Au-VO2 NCTFs is downward shifted by similar to 16 K and forward shifted 6 K. The V L-edge and O K-edge have been investigated. The basic electronic parameters such as the covalency (W) have been tuned. The relationship between bandwidth and the MIT temperature has been clearly elucidated a linear relationship. The experimental results demonstrate that MIT in VO2 is BC-MIT which improved our understanding of the electron correlation effect in VO2 systems.