We　show　that　entanglement　of　multiple　atoms　can　arise　via　resonant　interaction　with　a　displaced　thermal　field　with　a　macroscopic　photon-number.　The　cavity　field　acts　as　the　catalyst,　which　is　disentangled　with　the　atomic　system　after　the　operation.　Remarkably,　the　entanglement　speed　does　not　decrease　as　the　average　photon-number　of　the　mixed　thermal　state　increases.　The　atoms　may　evolve　to　a　highly　entangled　state　even　when　the　photon-number　of　the　cavity　mode　approaches　infinity.　©　Rinton　Press.