A theoretical method of calculating multiple scattering of P and SV waves by arbitrarily arranged and circular cross-section multi-row elastic piles barrier is presented, which has covered the shortage that single scattering hypothesis is reasonable only under the cross-section size is negligible compared with the incident wave length, and this method is considered interference phenomenon as well. It is defined first order scattering of P and SV waves by an arbitrary elastic pile s, the second order scattering is regarded as the first scattering waves induced, thus all scatterers and successive orders follow this multiple scattering process. Every order of scattering satisfies stress and displacement continuity conditions at pile-soil interface and an iteration relationship of wave functions is obtained. Total scattering wave field is achieved by composing all orders scattering by scatterers. It is investigated the influences of scattering orders, separations of piles, distances of pile-rows and shear modulus ratio of pile and soil etc. on isolation effectiveness of pile barriers, which are some of referred basis in practical engineering vibration isolation design.