Abstract: A hybrid algorithm combining the semianalytical recursive convolution(SARC) with time-domain physical optics is proposed to decrease the resource consumption in computing the transient near-field scattering from rough surface using the full-wave approaches. In this hybrid method, the computing work is divided into the time-domain physical optics (TDPO) solution of the equivalent resource on rough surface and the calculation of the near-field radiation with the time-domain Huygens’ principle. The SARC is presented to improve the efficiency for solving the time-domain convolution of equivalent source and Green’s function in the near-field radiating analysis based on the idea of the digital signal processing. Firstly, the Green’s function in the Huygens’ principle is approximated as a sum of exponential function, and then the SARC is applied to update the time-domain convolution to obtain the transient radiation from the equivalent resource on rough surface. The proposed SARC-TDPO algorithm is used to obtain the transient near fields scattered from a sea surface with the PM spectrum. And this hybrid method is verified through comparison with the scattering near fields computed by the traditional finite difference time domain (FDTD) methods. The results show that calculating efficiency of the proposed algorithm can be significantly improved and the precision can also be guaranteed. Moreover, the further the field point away from rough surface, the higher the relative efficiency is.