The invention discloses leech fibrinolytic protein prepared by employing the following preparation method: (1) extracting a leech fibrinolytic protein crude product; (2) performing QSephroseFastFlow ion exchange column chromatography on the above leech fibrinolytic protein crude product, performing linear elution by using a NaCl solution, collecting the eluate corresponding to a fifth elution peak, concentrating and drying, so as to obtain leech fibrinolytic crude protein; and (3) dissolving the above obtained leech fibrinolytic crude protein with distilled water, performing SephacrylS-200 gel filtering chromatography, eluting with distilled water, getting the eluate corresponding to a first elution peak, concentrating and drying, so as to obtain leech fibrinolytic protein. Through in-vitro fibrinolysis experiments and animal in-vivo thrombolysis experiments of leech fibrinolytic protein, results show that leech fibrinolytic protein disclosed by the invention has obvious dissolving effect on fibrin formed in a blood clotting process, and has dissolving effect on thrombus in a model mouse. The results indicate that leech fibrinolytic protein has great exploitation application prospect for preparing thrombolytic drugs.