China has launched recently its national 3D mapping program to build 3D realistic geospatial landscape model (3DRGLM), and has been considered as an important step towards establishing Digital China and transforming our geospatial industry. It is a huge spatio-temporal information engineering with many complex technical and management factors, and is becoming a challenging task for governmental agencies and academy societies. The paper has introduced the motivation and fundamental concepts of the 3DRGLM, i.e., moving from traditional 2~2.5D cartographic products to 3D realistic geospatial landscape products, from simple data supply to spatio-temporal empowerment, from digital to intelligentized mapping. The overall architecture of national 3DRGLM was then proposed and it has a number of key components, such as the data product system for generating geospatial entities, geospatial scenes and realistic geospatial scenes, the service system designed to support spatio-temporal connection, computing, and intelligence, as well as its digital-intelligentized hybrid technological support system. The 3DRGLM has some special key technological issues, including geospatial entity modeling, stereo reconstruction of muti-dimensional real space, realistic description and geospatial temporal knowledge service. Finally, this paper discussed five typical application scenarios of 3DRGLM, including application of 3DRGLM in digital economy, digital governance, digital living, digital culture, and digital ecological civilization. In order to achieve a successful establishment and an in-depth application of national 3DRGLM, it is necessary to carry out strategic planning, enhance scientific and technological innovation and promote cross-border and multi-disciplinary collaboration.