At present, the clinical diagnosis of and treatment methods for hepatic carcinoma still fail to fully meet the needs of patients. The integrated theranostic system, in which functional materials are used to load different active molecules, created a new developmental direction for the combination treatment of hepatic carcinoma, realizing the synchronization of diagnosis and treatment. In this study, polydopamine (PDA), which has the functions of self-assembly, encapsulation, photothermal conversion, and photoacoustic interaction, was used as the carrier material. The IR780, a near-infrared fluorescence imaging (NIFI), photoacoustic imaging (PAI), and photothermal therapy (PTT) agent, and paclitaxel (PTX), a broad-spectrum chemotherapy drug, were selected to build the NIF/PA dual-mode imaging and PTT/chemo synergistic theranostic nanoparticles (DIST NPs). The DIST NPs have a 103.4 ± 13.3 nm particle size, a weak negative charge on the surface, good colloidal stability, slow and controlled drug release, and high photothermal conversion ability. The experiments results showed that the DIST NPs have a long circulation in vivo, high bioavailability, high biocompatibility, and low effective dose. DIST NPs showed an excellent NIFI/PAI dual-mode imaging and significant synergistic antitumor effect in hepatic carcinoma models. DIST NPs met the initial design requirements. A set of fast and low-cost preparation methods was established. This study provides an experimental basis for the development of new clinical theranostic methods for hepatic carcinoma.