Abstract: Lipid nanoparticle (LNP) represents one of the most clinically advanced drug delivery system for therapeutic nucleic acids, offering high drug loading capacity, excellent stability, and favorable biocompatibility. However, their ability to fulfill clinical demands still faces limitations, including hepatic aggregation characteristics, challenges in endosomal escape, immunogenicity, and safety issues related to repeated administration. Utilizing high-throughput screening technologies and artificial intelligence (AI)-assisted design of ionizable lipids, LNP development has shifted from empirical conventional trial-and-error methodology toward rational, data-driven paradigms. This review focuses on the formulations and structural composition of LNPs; and ionizable lipids, cholesterol, helper lipids, and polyethylene glycol (PEG)-lipids are systematically analyzed for how they influence the physicochemical characteristics, in vivo distribution, cellular uptake, and intracellular nucleic acid release of LNPs. It further provides a comprehensive overview and future perspectives on innovative strategies for extrahepatic targeting, cellular uptake modulation, endosomal escape optimization, and safety enhancement. Moreover, this review summarizes the advances in the utilization of LNPs for the conveyance of siRNA, mRNA, gene editing agents, and proteins, and elucidates how intelligent material design, synergistic optimization of multiple components, and precise delivery modulation technologies assist LNPs in surmounting existing developmental bottlenecks, thereby providing theoretical foundations and research perspectives for constructing safe, efficient, and personalized nanomedicine delivery platforms.