A new procedure is developed to simulate the range-Doppler signatures for objects floating on time-evolving sea surface. First, a time-varying scene consisting of a series of integrated sea-object models is constructed by the time-evolving rough sea surface and the micro-motioned objects driven by the sea dynamics. The shooting and bouncing ray (SBR) technique, combined with high-frequency asymptotic methods is used to calculate electromagnetic (EM) scattering from the integrated sea-object scene at each specific radar pulse repeat time interval, where a unique strategy is proposed for the processing of EM coupling as well as occlusion among the simulated scene. Numerical results are presented to demonstrate the validity and usefulness of the proposed procedure.