Molecular targeted photosensitizer and preparation method thereof

A molecular targeted photosensitizer and a preparation method thereof are disclosed. The molecular targeted photosensitizer consists of folic acid porphyrin, R1, R2 and R3 in the molecular structural formula of folic acid porphyrin are independently hydroxyl, straight-chain or branched-chain hydrocarbon, n in the molecular structural formula ranges from 1 to 20. The preparation method is as follows: alkylation reaction is carried out on monohydric porphyrin and dihalohydrocarbon to generate halogen porphyrin, and then Gabriel reaction is carried out with phthalimide potassium to generate amide porphyrin which is hydrolyzed by hydrazine to obtain primary amine porphyrin; finally, amination reaction is carried out on primary amine porphyrin and folic acid to obtain the folic acid porphyrin. The raw materials used by the preparation method of the invention are stable and accessible, the reaction condition is mild, the yield is high, the generated reactant has good targeted therapy to tumor cell, partial photosen