Abstract: The integrated positioning, navigation and timing (PNT) service system is an important support for the operation and development of China’s digital economy and society. The comprehensive PNT application service with BDS-3 as the core is the development focus of China’s future spatiotemporal information technology and industry. Firstly, the concept of “on-demand elastic and scalable integrated PNT application service system” was defined, and an application service framework of “integrated white box (software defined node)+unified network (elastic and scalable system)+network signaling field diagram (intelligent operation and management services)+intelligent game (complex task decision-making)” was proposed. A comprehensive PNT application service technology route of “fixed base, strong network, and efficiency enhancement” was designed, The comprehensive PNT application service mode of “public network+private network+mobile network” was given, and the application prospect was prospected. In the future, a comprehensive spatiotemporal application service system with the core of “BeiDou+LEO+5G+pseudosatellite+location big data” will provide BeiDou indoor and outdoor ubiquitous spatial cloud and terminal collaborative precise location services for multi-level and multi-disciplinary users, and assist in the digital transformation of the entire society.