In the present study, we found that that MSCs-Exo promoted the transformation of M1 type macrophages to M2 type macrophages, and IDO-overexpressed MSCs-Exo had a higher efficacy to inhibit the process of renal fibrosis and apoptosis in IRI mouse kidney model, accelerating the self-repair process in mice after IRI. Here, IDO1 is linked to renal fibrosis.