The invention belongs to the technical field of photosensitizers, and particularly relates to a 
photosensitizer and a preparation method and application for improving the photodynamic performance of the 
photosensitizer. The structural general formula of the prepared 
photosensitizer is shown in the specification, r1 is I, Br or H; x is I, Br or Cl; and R2 is a linear chain or branched chain 
alkyl group of C1-C6. According to the application of the photosensitizer provided by the invention, the photosensitizer is a near-
infrared photosensitizer, is high in optical performance, can specifically target 
tumor cells, and meanwhile, has small and even no damage to normal cells; the defect that two different medicines, namely the photosensitizer and the 
lonidamine, have different metabolic pathways 
in vivo and are difficult to reach the 
tumor site at the same time is overcome; the invention further provides a preparation method of the near-
infrared photosensitizer, raw materials are easy to obtain, 
reaction conditions are mild, and purification is easier.