This paper explores the importance of low-power digital integrated circuits (IC) in technological development and everyday applications, especially their key role in modern electronic devices such as smartphones and advanced medical devices. With the advent of the digital age, the design efficiency and energy efficiency of low-power IC have a direct impact on device performance and sustainability. Based on the design basis of low power IC, CMOS technology and its power consumption model are discussed in detail, and dynamic and static power consumption is reduced by means of dynamic voltage frequency regulation, multi-threshold CMOS technology and clock gating technology. In addition, the paper explores in depth the verification and optimization process of low-power designs, emphasizing the importance of experiments and simulations in accurately evaluating and adjusting power consumption. Finally, the paper focuses on the key applications of low-power design in mobile devices and medical devices and presents some practical application cases. The research in this paper will help to promote the wide application of low-power IC in different fields and contribute to scientific and technological progress and social needs.