China is building the largest national park system in the world. There is an urgent need to carry out large-scale biodiversity surveys and monitoring, so as to provide important support for the construction and development of national parks. The emerging technique of passive acoustic monitoring (PAM) has become an increasingly favored method for large-scale biodiversity research in recent years. This paper provides an overview of the concept, development and advantage of PAM technology, and introduces the roles of this technology in biodiversity conservation in national parks from five aspects, including dynamic change monitoring of soundscape, biodiversity research, relationship between organism and environment, impact of anthropogenic activities on organisms as well as ecological services and ecological protection of the soundscape. Additionally, the paper discusses the developmental trends of acoustic surveys and monitoring in national parks from four perspectives, that is, building a large-scale soundscape monitoring network, assisting the protection of endangered species, improving acoustic storage and analysis techniques, and the development, utilization and conservation of soundscape resources. Finally, this paper discusses the current challenges of the PAM technology and offers a perspective on its future. In summary, PAM technology will become an important method of ecological protection and natural resource utilization, and play a significant role in the construction and management of Chinese national parks.