A targeting thymidine kinase photosensitizer and pharmaceutical composition and use for cancer treatment thereof is provided, which improves the selectivity of photosensitizers to tumor cells, has better tolerance, can reach maximum blood concentration in 24 hours, has a bigger conjugated system, a longer absorption wavelength and an advantage in treating depth tumors; the wavelength area does not need to consume much energy of a light-output device and even LEDs can be used, which render PDT more practical and economical. The targeting thymidine kinase photosensitizer can be used for diagnosis and for treating prostatic carcinoma via the guidance of fluorescence imaging. The pharmaceutical composition uses a combination of a chemotherapeutic agent and the targeting thymidine kinase photosensitizer, which further improves the therapeutic effect of the PDT method, expands the application range for tumors and has good effects on metastatic tumors as well.