Abstract Substantially different from traditional combinatorial-treatment of photothermal therapy (PTT) and photodynamic therapy (PDT) by using multi-component nanocomposite under excitation of separate wavelength, a novel single near infrared (NIR) laser-induced multifunctional theranostic nanoplatform has been rationally and successfully constructed by a single component black titania ( B –TiO 2− x ) for effective imaging-guided cancer therapy for the first time. This multifunctional PEGylated B –TiO 2− x shows high dispersity/stability in aqueous solution, excellent hemo/histocompatibility and broad absorption ranging from NIR to ultraviolet (UV). Both in vitro and in vivo results well demonstrated that such a novel multifunctional theranostic nanoplaform could achieve high therapeutic efficacy of simultaneous and synergistic PTT/PDT under the guidance of infrared thermal/photoacoustic (PA) dual-modal imaging, which was triggered by a single NIR laser. This research circumvents the conventional obstacles of using multi-component nanocomposites, UV light and high laser power density. Furthermore, negligible side effects to blood and main tissues could be found in 3 months' investigation, facilitating its potential biomedical application.