With the rapid development of biomedical engineering, implantable electronic devices have become indispensable tools in clinical therapy. However, their limited battery life has become a critical bottleneck restricting their long-term in vivo application. Traditional approaches such as surgical battery replacement or percutaneous wired power supply have problems such as surgical risks, postoperative infections, and heavy patient burdens. Therefore, non-invasive wireless power transmission technology is regarded as an ideal solution to break through the bottleneck in this field. Among various external energy sources, infrared light, especially near-infrared-II (NIR-II) light (1000―1350 nm), exhibits enormous potential for wireless power supply of implantable devices due to its high penetration in biological tissues, high maximum permissible exposure for biological tissues, and favorable controllability. This paper first outlines the challenges of powering implantable devices and the limitations of existing wireless powering schemes (such as radio frequency waves and ultrasound), and then demonstrates the comprehensive advantages of infrared light (i.e., near-infrared subcutaneous generators). Subsequently, focusing on the two core aspects of light transmission in vivo and energy conversion, this paper systematically reviews the core technical strategies of near-infrared subcutaneous generators, including efficient light energy delivery via tissue optical transparency strategies or transcutaneous hydrogel optical fibers, and efficient and safe powering through photothermal-electric conversion mechanisms or photoelectric-thermoelectric synergistic conversion mechanisms. Finally, the future challenges and development directions of near-infrared subcutaneous generators are discussed, aiming to provide references for in-depth research and technological transformation in this field.