Uniform and well-dispersed walnut kernel-like mesoporous silica nanoparticles (MSNs) with diameters about 100 nm have been synthesized by a templating sol-gel route. After an annealing process, the as-obtained sample (DLMSNs) inherits the well-defined morphology and good dispersion of MSNs, and exhibits bright white-blue luminescence, higher specific surface area and pore volume, and better biocompatibility. The drug loading and release profiles show that DLMSNs have high drug loading capacity, and exhibit an initial burst release followed by a slow sustained release process. Interestingly, the luminescence intensity of the DLMSNs-DOX system increases gradually with the increase of cumulative released DOX, which can be verified by the confocal laser scanning images. The drug carrier DLMSNs can potentially be applied as a luminescent probe for monitoring the drug release process. Moreover, the DLMSNs-DOX system exhibits potent anticancer effect against three kinds of cancer cells (HeLa, MCF-7, and A549 cells).