The invention relates to a Parischnogaster spp vespo bee venom polypeptide effective part and preparation and medical application thereof. Specifically, the effective part is prepared by dialyzing in the Parischnogaster spp rough bee venom with a dialysis membrane with molecular weight cutoff of 25KDa, and drying the eluate by means of freeze drying or concentration under reduced pressure. By a series of pharmacodynamic experiments, the inventor verifies that the biotoxin polypeptide effective part and transdermal absorption preparation thereof have the effects of remarkably preventing and treating generation of cerebral thrombus, recovering capacity for action of animal with cerebral palsy and relieving ischemic brain injury, have stronger pharmacodynamic performance than the first-line medicines, such as plavix and Xingnaojing, can be expectedly used for preparing cardiovascular and cerebrovascular disease prevention and treatment biochemical drugs for preventing and treating ischemic cardiovascular and cerebrovascular diseases, such as myocardial infarction, cardiovascular thrombosis, cerebral thrombosis, cerebral infarction and acute/chronic cerebral apoplexy, and sequelae caused by cerebral infarction injury, such as hemiplegia, hemidysesthesia, hemianopsia, facial-tongue paralysis, aphasia and general paralysis.