Metal-organic frameworks as a powerful platform for drug delivery have attracted significant attention in recent years. In this study, mesoporous iron-metal-organic framework nanoparticles (mesoMOFs) were synthesized via the double-template method. Cetyltrimethylammonium bromide (CTAB) and citric acid (CA) were chosen as the double-template agent. The mesoMOFs were characterized by EDX, elemental analysis, TG, BET, SEM, TEM, and DLS. The anticancer drug doxorubicin hydrochloride (DOX) was encapsulated in the mesoMOFs, and the DOX loading content was up to 55 wt%. The mesoMOFs are non-toxic to both 4T1 breast cancer cells and 3T3 fibroblasts. The DOX-loaded mesoMOFs exhibit a better anti-tumor effect than free doxorubicin in vitro. The in vivo anticancer activities of the DOX-loaded mesoMOFs were investigated in 4T1 breast cancer-bearing mice. The intratumoral injection of DOX-loaded mesoMOFs revealed that the mesoMOFs could significantly reduce the systemic toxicity of DOX, sustainably release DOX, and maintain an effective DOX concentration for chemotherapy. The DOX-loaded mesoMOFs exhibit excellent therapeutic efficacy and low side effects in local chemotherapy.