In order to study the influence of the action of coupling earthquake to sliding base-isolation structure and improve its effect of vibration reduction by means of optimizing its major parameters. The theory of sliding base-isolation structure under the action of coupling earthquake is studied. A dynamic differential equation is developed. Seismic response analysis of 6-storey sliding base-isolation structure is processed, the results by exemplification show that the peak values of relative acceleration, relative displacement and inter-storey shear force of sliding base-isolation structure increase in different degree under the action of coupling earthquake. The increments increase with the action of earthquake in vertical direction increasing. In view of that SGA has such frequent shortcomings as premature convergence, oscillation and over-randomization in iterative process, a new genetic operator named transgenic operator had been developed for the purpose of improving SGA. Moreover, FBSA is proposed and combined with IGA. The parameters optimization model for the sliding base-isolation structure is set up. The various earthquake responses of sliding base-isolation structure get better control after it is optimized with IHGA. The results by exemplification show that IHGA is an efficient optimal method for parameters and layout optimization of sliding base-isolation structure.