In this communication, we present the combination of a high scalability implementation of the multibranchmultiresolution preconditioner with the domain decomposition method for the electromagnetic analysis of geometrically complex strutures with different levels of multi-scale features and discretized with a possible non-conformal mesh. Finally, a numerical experiment is shown to illustrate the great efficiency of the proposed approach for the solution of large multi-scale objects.Index Terms-Domain decomposition method (DDM), multiresolution (MR) preconditioner, multibranch Rao Wilton Glisson (MB-RWG) basis functions, method of moments (MoM), multilevel fast multipole algorithm (MLFMA).