The invention discloses a boron-containing compound for BNCT and a preparation method and application thereof, and belongs to the field of medicines. The novel boron-containing compound is obtained through condensation, ammonolysis and cyclization reaction, and is easy to prepare, low in cost, and has good biological properties; the boron-containing compound is better than BPA on uptake, accumulation and reservation of tumour cells, free of any signs of toxicity, and has a good application prospect in BNCT. Moreover, the boron-containing compound is further expected to be a clinical potential positron emission tomography tumor imaging agent after being labeled through radioactive elements, and creates the advantage conditions for diagnosis of malignant tumor, identification of benign and malignant diseases, exploration of systematic metastatic lesions and the like.