Abstract: Traditional marine hydrodynamic monitoring uses large anchored buoys to collect data, which is expensive and space confined. This paper developed a surface wireless network with a radius of 100km, which can be quickly applied in the hydrodynamic monitoring by combination of a large number of abandoned microbuoys with Beidou positioning. The technology can solve the problems of high cost and insufficient data refinement in the traditional marine hydrodynamics monitoring, which uses largescale mooring buoy for data collection at a fixed position. Results of many sea trails show that the method is practical and effective when used for tracking the sediment deposition and marine floating garbage, monitoring the balance of tidal dynamic, assessing the quality of mariculture environment and so on.