Service Composition enables a new way to create new services by assembling independent service components. However, a considerable network communication cost much when the flood broadcast method is used extensively to carry out the service route and composition in the service composition model at present. A new multi-layer structure model called STBM (Spanning Tree Based Model) has been proposed. An effective algorithm of service composition has been developed based on this model. Theoretical analysis showed that STBM has the lower average network communication stream quantity than Spidernet.