Photoacoustic imaging and photothermal therapy are achieved using organic nanopreparations absorbed by the NIR two 2. Photoacoustic imaging is a technique that uses laser excitation to generate acoustic signals and reconstruct ultrasonic signals, with the advantages of high resolution, high contrast and deep penetration depth. Photothermal therapy is a technique that uses laser to convert light energy into heat energy, thus causing increasing the temperature of tumor tissue and causing tumor necrosis, and has the advantages of non-invasive, controllable and selective. The organic nano preparation absorbed by NIR region 2 can be used as a common probe and carrier for photoacoustic imaging and photothermal therapy to achieve accurate diagnosis and treatment of tumors. Multimodal imaging using inorganic nanomaterials and photodynamic therapy. Multimodal imaging is a use of different imaging modalities to obtain different aspects of information, thus improving imaging accuracy and reliability. Photodynamic therapy is a technique that uses laser-activated photosensitizers to produce reactive oxygen species, thereby causing tumor cell death, with the advantages of low toxicity, high selectivity and low drug resistance. Inorganic nanomaterials absorbed by NIR Zone 2 can be used as common probes and carriers for multimodal imaging and photodynamic therapy to achieve comprehensive detection and treatment of tumors.