Abstract: The oral cavity is a complex microecosystem that provides a suitable habitat for diverse microorganisms, including bacteria, archaea, fungi, viruses, and protozoa. The microbial communities in the oral cavity form a stable microecology through complex interactions and environmental adaptation. In a healthy oral microenvironment, various microorganisms maintain microecological balance through signal communication, material exchange, competition and cooperation for resources and environmental conditions, quorum sensing, and environmental adaptation. In contrast, an imbalanced oral microecology can lead to oral diseases such as endodontic and periodontal diseases, and may even affect systemic health. Natural products have attracted significant attention for maintaining oral microecological balance due to their potential antibacterial, anti-inflammatory, biofilm-inhibiting, and microecology-regulating properties. This article systematically reviews the characteristics of natural products, their mechanisms for regulating oral microecological balance, and their application prospects and limitations in oral disease prevention and treatment, providing a reference for the use of natural products in maintaining oral microecological balance.