According to the National Aeronautics and Space Administration (NASA) of the United States, a digital twin is a virtual representation of mimicking the entire lifecycle of its corresponding physical entity by integrating physical models, sensors, historical operational data, and additional relevant information. Coral reefs, renowned as one of the most biodiverse ecosystems on the planet, stand as an ideal and important scene for the advancement of digital twin technology within oceanic realms. Despite the utilization of remote sensing techniques, including satellite and hyperspectral systems, which offer insights into the information of morphology, depth, and temperature of coral reefs, the comprehensive data acquisition essential for coral ecosystems – encompassing details like fish and coral species, substrates, and information on coral bleaching and damage – remains heavily rely on conventional method - transect-based observation. Our research initiative commenced with traditional methodologies for establishing foundational data. The endeavor to develop a digital twin for coral reefs involved (1) the creation of physical models representing corals and associated components of the marine environment, (2) the application of digital image processing for coral identification, and (3) involving basic environmental parameters in the digital twin platform for coral reefs. Our study gives an example of the digital twin in typical oceanic habitats, which will be beneficial for related oceanic areas, such as coastal region monitoring and the estimation of blue carbon sequestration.