The hydrodynamic of marine data buoy and its mooring system has an important im-pact on its reliability, viability and adaptability at sea. In this paper, the numerical simulation, which is combined with physical model test verification, is adopted for studying hydrodynamic of data buoy, by using the measured data in the northern sea area of Chu Island, Weihai, Shandong Province, China. In the numerical analysis, the Advanced Quantitative Wave Analysis (AQWA) module in ANSYS is used, which includes frequency domain analysis and time domain analysis. The hydrodynamic performance of three different mooring systems, i.e. slack type, inverted S type and tension type, under the action of wind and waves coupling is studied. The model test of the buoy was carried out at the Environmental Laboratory in the National Ocean Technology Center of the Ministry of Natural Resources of China, and the scale of the model is determined to be 1:5, according to the laboratory test capacity and buoy prototype size. The results show that the inverted S type mooring system has higher reliability, while the tension type mooring system can obtain more accurate observation data, and the performance of the slack mooring system is between the two, among the three types of mooring systems. The research results can provide a reference for the design of other marine buoys and their mooring systems, and the validated numerical simulation method can be applied to the study of the survival performance of the buoy in long-term and extreme sea condition.