The purpose of this study was to investigate the effects of cardiac homing peptide (CHP) engineered bone marrow mesenchymal stem cells (BMMSc) derived exosomes (B-exo) loaded miRNA-499a-5p on doxorubicin (DOX) induced cardiotoxicity. miRNA chip analysis was used to analyze the differences between DOX induced H9c2 cells and control group. CHP engineering was performed on BMMSc derived exosomes to obtain C-B-exo. miRNA-499a-5p mimic was introduced into C-B-exo by electroporation technology to obtain C-B-exo-miRNA-499a-5p. DOX was used to establish a model of cardiotoxicity to evaluate the effects of C-B-exo- miRNA-499a-5p in vivo and in vitro . Western blot, immunohistochemistry, immunofluorescence, and other molecular biology methods were used to evaluate the role and mechanism of C-B-exo-miRNA-499a-5p on DOX induced cardiotoxicity. miRNA chip analysis revealed that miRNA-499a-5p was one of the most differentially expressed miRNAs and significantly decreased in DOX induced H9c2 cells as compared to the control group. Exo-and B-exo have a double-layer membrane structure in the shape of a saucer. After engineering the CHP of B-exo, the results showed that the delivery of miRNA-499a-5p significantly increased and significantly reached the target organ (heart). The experimental results showed that C-B-exo-miRNA-499a-5p significantly improved electrocardiogram, decreased myocardial enzyme, serum and cardiac cytokines, improved cardiac pathological changes, inhibited CD38/MAPK/NF-κB signal pathway. In this study, C-B-exo-miRNA-499a-5p significantly improved DOX-induced cardiotoxicity via CD38/MAPK/NF-κB signal pathway, providing a new idea and method for the treatment of DOX induced cardiotoxicity.