Abstract: Cathodic cage plasma nitriding (CCPN) is an advanced technique of plasma nitriding, which can form a unique nitrided layer/deposition film on the substrate with overcoming the drawbacks of the edge effect, hollow cathode effect and arcing. The introduction of a cathodic cage in CCPN provides a homogeneous heating source and increases the plasma density. Moreover, the introduction of the cathodic cage greatly broadens the application scope of this technology, making it applicable to various substrate materials, including alloys, pure metals, polymers and carbon materials, and enabling the formation of diverse deposition coatings. This review aims to deeply elaborate on the process principle and technical advantages of cathodic cage plasma nitriding, and systematically analyze the specific impact of different process parameters on the nitriding effect. At the same time, this paper will also explore the broad application prospects of this technology in enhancing material hardness, improving friction and wear properties, enhancing corrosion resistance, endowing antibacterial functions and optimizing surface electrical conductivity. In addition, this paper will analyze the existing problems and challenges in current research and propose future research directions and development trends. It is hoped that this review can provide beneficial references and inspirations for researchers in related fields, and promote the continuous innovation and application scope expansion of cathodic cage surface modification technology.