The invention relates to a distributed marine radar system, which comprises two X waveband radar modules, two S waveband radar modules, a selector switch module, a control module, a signal synthesizing module, a display module and a power module. The two X waveband radar modules and the two S waveband radar modules are connected with the input terminal of the selector switch module; the output terminal of the selector switch module is connected with the display module through the signal synthesizing module; the selector switch module is controlled by the control module to work; and the selector switch module, the control module and the display module are powered by the power module. Because the two X waveband radar modules and the two S waveband radar modules symmetrically arranged on a drilling ship are adopted, and each radar is in charge of a part of a scanning area, a whole sea surface image is displayed at the terminal of the display module after the received signals of each radar are synthesized. The distributed marine radar system can be widely applied in various oil exploration and exploitation fields.