In this study, we introduced a targeting polymer poly(ethylene glycol)-folic acid (PEG-FA) on the surface of polydopamine (PDA)-modified mesoporous silica nanoparticles (MSNs) to develop the novel nanoparticles (NPs) MSNs@PDA-PEG-FA, which were employed as a drug delivery system loaded with doxorubicin (DOX) as a model drug for cervical cancer therapy. The chemical structure and properties of these NPs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, N adsorption/desorption, dynamic light scattering-autosizer, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The pH-sensitive PDA coating served as a gatekeeper. The in vitro drug release experiments showed pH-dependent and sustained drug release profiles that could enhance the therapeutic anticancer effect and minimize potential damage to normal cells due to the acidic microenvironment of the tumor. These MSNs@PDA-PEG-FA achieved significantly high targeting efficiency, which was demonstrated by the in vitro cellular uptake and cellular targeting assay. Compared with that of free DOX and DOX-loaded NPs without the folic targeting ligand, the FA-targeted NPs exhibited higher antitumor efficacy in vivo, implying that they are a highly promising potential carrier for cancer treatments.