The urgent need of environmental pollution prevention and ecological civilization construction in the new period has promoted the rapid development of environmental remote sensing monitoring technology. Over the past 20 years and more, China’s environmental remote sensing monitoring has gradually entered the main battlefield of national ecological and environmental protection from scratch. It has become an indispensable and important technical means for national environmental management and decision making, playing a key supporting role. Faced with the new situation and new requirements of implementing the strictest ecological and environmental protection system, scientific, precise, and law-based pollution control, China’s environmental remote sensing monitoring is faced with unprecedented opportunities and challenges. This paper first reviews the work history of environmental remote sensing monitoring in China with the construction and application of environmental monitoring satellites as the main line. Starting with the research overview of typical key technologies, this paper then summarizes the progress of key technologies of water environment remote sensing monitoring, atmospheric environment monitoring, and ecological environment monitoring. Combined with the development of advanced technologies, such as high-performance Earth observation and big data, the frontier issues of subsequent environmental satellites, active remote sensing discovery of ecological environmental problems, big data of remote sensing monitoring, and environmental remote sensing inversion based on deep learning, are discussed. The problems and development direction of environmental remote sensing in China are pointed out. The development and application prospects of relevant technologies are analyzed and prospected. The national environmental remote sensing monitoring technology system has been successfully established, and the operational capability of environmental remote sensing has been basically formed. These achievements are due to the great attention of relevant national departments and the joint efforts of the author’s team and relevant researchers. A new generation of environmental monitoring satellites featuring high-resolution detection is rapidly developing, The technical performance of the environmental satellite payloads will be greatly improved. The study of environmental remote sensing mechanism is attracting much attention, and the accuracy and efficiency of environmental remote sensing monitoring will be improved. China’s environmental remote sensing monitoring is integrated with artificial intelligence, big data, and other new technologies, and accelerates from the model-driven era centered on mathematical modeling to the data-driven era characterized by intelligent perception. These conditions will give birth to new environmental remote sensing application scenarios and big data products and make environmental remote sensing monitoring develop toward intelligent perception, intelligent warning, intelligent decision, and intelligent service.