The Haiyang II D satellite (HY-2D) has been officially delivered to the Ministry of Natural Resources and put into operational application. The HY-2D satellite was successfully launched from Jiuquan on May 19, 2021, carrying five effective payloads including radar altimeter, microwave scatterometer, calibration radiometer, data collection system and automatic ship identification system. After the launch, the National Satellite Ocean Application Service of the Ministry of Natural Resources, together with other major system construction units of satellite, measurement and control, and ground, carried out tests on the whole process of satellite data reception, preprocessing, processing, distribution and application. On-site calibration inspection was carried out, and standardized processing of data products such as sea wind field, sea wave and sea height was realized. Meanwhile, a number of industrial application tests were carried out jointly with user departments such as meteorological, disaster reduction, water conservancy and agriculture, and all on-orbit tests were successfully completed. HY-2D satellite is an important autonomous satellite with the Ministry of Natural Resources as the main user. After the networking operation of the satellite and the on-orbit HY-2B/C satellite, the satellite is jointly constructed into China's first marine dynamic environment satellite constellation. The completion of the constellation has increased the ability to obtain the information of the sea surface wind field of over 80% of the world's sea areas from about 12 hours in the past to 6 hours, significantly increasing the frequency of observation of marine disasters such as typhoons, storm surges and large waves, and providing more accurate, comprehensive and timely information on the marine dynamic environment for marine disaster prevention and reduction. The on-orbit test results show that the HY-2D satellite has application advantages in marine environmental monitoring, global climate change research and disaster prevention and reduction, which can effectively support the main business of natural resources and take into account various businesses in the fields of meteorology, agriculture, transportation and disaster reduction. The operational application of the satellite shows that the HY-2D satellite has realized networking operation with the HY-2B/C satellite. In the aspect of marine environmental prediction, the initial field information of sea height, sea wind field and effective wave height is provided for the marine and meteorological numerical prediction system, which improves the prediction precision and prediction timeliness. In terms of marine disaster prevention and reduction, the satellite has an efficient tropical cyclone information acquisition capability to provide first-hand observation data for flood season emergency consultation. In addition, the satellite also has broad application prospects in such industries as meteorology, disaster reduction and agriculture. It also plays an important role in the international earth observation system, and provides a strong technical support for China to participate deeply in the global governance system.