Abstract: Magnetron sputtering coating technology is a crucial technique for fabricating various functional thin films in today's high-tech products. With the advancement of high technology, high-end manufacturing, and the improvement of living standards, magnetron sputtering coating technology faces more diversified demands and higher performance requirements, driving its continuous progress. This paper presents recent developments in magnetron sputtering coating technology, focusing on the principles of unbalanced closed-field magnetron sputtering and its application effects in coating tools, molds, and wear-resistant components. In an unbalanced magnetron sputtering target, the magnetic flux density between the outer and central magnets is unevenly distributed, pushing the magnetic field intensity forward and expanding it outward, thereby extending the range of electron confinement by the magnetic field. When unbalanced magnetron sputtering targets are installed in the coating chamber with opposite magnetic polarities arranged adjacently—where the outer magnetic poles of two targets are N-S and attract each other—the entire coating chamber’s magnetic fields interconnect to form a closed field. This configuration confines electrons within the chamber to rotational motion, increasing collision probabilities between electrons and argon gas or metal film atoms. Consequently, it enhances deposition rates, improves metal ionization efficiency, facilitates compound film deposition, and elevates the overall performance of magnetron sputtering. The planar unbalanced closed-field magnetron sputtering coating machine has successfully deposited CrN, WC hard coatings, and DLC friction-reducing coatings on wear-resistant parts tempered at 200 °C, expanding the application range of hard coating deposition. By employing the magnetron sputtering technology with rotating tubular columnar unbalanced closed-field targets, where the magnetic polarities of adjacent columnar targets are arranged in opposite directions, a closed magnetic field is also formed within the coating chamber. This enables the deposition of denser nano-multilayer films. In unbalanced magnetron sputtering coating machines, matching the high-density electron flow emitted by arc discharge can further increase collision probability for auxiliary deposition, thereby enhancing deposition rates and metal ionization rates. This results in high-hardness, finer, and denser nano-multilayer films, which are expected to extend the service life of components operating in wear and corrosion environments.The article also introduces several new technologies: using a medium-frequency power supply matching with twin targets to overcome target poisoning and anode disappearance phenomena during the deposition of dielectric films; adopting the “step-by-step deposition method” to avoid target poisoning and anode disappearance, thereby improving deposition rates and film quality; employing hot cathode-enhanced magnetron sputtering technology to increase the workpiece bias current by more than 20 times, enhance deposition rates, and improve the compactness of film structures; utilizing high-power supplies matched with unbalanced magnetron sputtering targets to increase the metal plasma density in the films, thereby boosting deposition rates, enhancing film-substrate adhesion, and improving the compactness and performance of film structures. The article anticipates that the application of these new technologies will undoubtedly propel magnetron sputtering coating technology to play a more significant role in high-tech and advanced manufacturing industries.