Multimode bioimaging probes with complementary advantages of imaging sensitivity and spatial resolution in a single drug delivery system have significant potential applications for clinical cancer diagnosis and chemotherapy. In this work, a polyethyleneimine-driven self-assembled lanthanide-doped CaF2 nanocluster was synthesized and used for fluorescence/MR imaging guided cancer chemotherapy. This nanocluster has an ordered pore structure and good cisplatin loading capacity. The release of cisplatin from this nanoplatform was triggered by acidic pH. In addition, this nanoplatform showed a high relaxation rate (4.91 mM(-1) s(-1)) and fluorescence signal. The cell assay results indicated that the nanoplatform was effectively internalized by HeLa cells and showed a good fluorescence/MR imaging ability and cell inhibition effect. In vivo experiment, the nanoplatform displayed excellent fluorescence/MR imaging and anticancer activity. In addition, the side effects of cisplatin on vital organs were significantly mitigated. Thus, this multifunctional nanoplatform is an excellent candidate for fluorescence/MR imaging guided cancer chemotherapy.