With the growth of investigations into the active components of breast milk and the continuous upgrading of the precise nutritional needs, infant formula milk powder has become the essential food matrix for meeting the nutritional needs of infants who cannot be breastfed, with profound implications for growth and development and future health. In recent years, novel active ingredients have been gradually discovered. The paradigm of infant nutrition support in mixed feeding has undergone a paradigm shift from macronutrient matching to active functional simulation. The related industries in China have also moved from a raw material-dependent pattern to a critical stage of precise targeting and industrial self-upgrade. This article systematically reviews the structural characteristics and functional mechanisms of five categories of novel active ingredients, including milk proteins, bioactive peptides, natural milk fats, breast milk oligosaccharides, and prebiotics. It summarizes the latest progress, based on high-sensitivity and high-throughput detection methods such as high-resolution chromatography-mass spectrometry, nuclear magnetic resonance spectroscopy, genotyping and microfluidic chip technology. It further discusses the development status and technical bottlenecks of emerging dairy processing technologies such as low-mineralization system construction, low-sugar glycosylation and low-allergenicity process control, and ultra-high pressure, pulsed electric field, etc. Finally, the significance of novel active ingredients for infants in mixed feeding is discussed. In the future, it is still necessary to deeply explore the key active ingredients in breast milk that remain uncharacterized, overcome technical bottlenecks in detection targeting and processing stability, strengthen collaborative research and development among industry, academia, and research institutions, and promote the development of China''s infant formula dairy industry towards high-quality directions of precise nutrition, functional adaptation, and independent innovation.