The actual rough sea surface is described by Pierson-Moscowitz (PM) spectrum and Monte Carlo method; the composite electromagnetic scattering from the double rectangular crosssection conductor columns above the rough sea surface is investigated using the hybrid methodthe Method of Moment with the Kirchhoff approximation. Angular distribution curves of composite scattering coefficient are obtained; and this coefficient that varies with the parameter of sea surface, rectangular cross-section conductor columns and incident waves is calculated in detail. The characteristics of the composite scattering coefficient from the double rectangular cross-section conductor columns above the rough sea surface are also obtained. Results show that the hybrid methodthe Method of Moment with the Kirchhoff approximation, compared to the traditional Method of Moment, can obtain higher accuracy. Moreover, the hybrid method can effectively reduce the computation time and memory footprint, and the performance becomes more favorable with the increase of the sizes of rough surface.