A current based hybrid method combining the MOM with the Kirchhoff approximation for analysis of scattering interaction between a two-dimensional infinitely long conducting target with arbitrary cross section and a 1-D rough sea surface with PM spectrum is proposed. The electromagnetic scattering region in the hybrid method is split into KA region and MOM region，respectively. The computational time of the hybrid method mainly depends on the number of unknowns of the target due to the induced current on the rough sea surface does not need to be calculated. The composite bistatic scattering cross section for the infinitely long cylinder above the rough sea surface with PM spectrum is calculated，the numerical results are compared and verified with those obtained by the conventional MOM，which shows the high efficiency of the hybrid method. Finally，the influence of the windspeed，the size and location of the target on the bistatic scattering cross section with different polarizations is discussed in detail.