The geostationary satellite has the characteristics of "standing high, seeing wide and staring long", and has the capability of large width imaging, continuous staring imaging and high timeliness imaging, which can realize the rapid response to various emergency observation tasks. The developments of high-orbit ocean remote sensing satellites and the array-gazing optical remote sensing system in ocean and coastal zones observation can fill the gap of dynamic monitoring on the marine environment in high orbit in China, and meet the urgent demand for observation and emergency monitoring of the surrounding sea areas, nearshore and islands of China. By analyzing the technical characteristics of the high-orbit optical remote sensing system for the ocean and coastal zone, a system design scheme has been put forward, in which many technologies are adopted, such as a large-aperture optical system with low stray light, low polarization and multi-spectral features, a high improvement in the signal-to-noise ratio, and an on-board calibration with high precision. Based on this, the prototype development and system testing have been completed, and combined with field tests, the feasibility of the core indicators has been effectively verified, laying a technical foundation for the implementation of the high-orbit optical remote sensing system project for the ocean and coastal zone.