Snake-poison substitute medicine for giving up drug-taking and curing senile dementia and its preparation method

The present invention relates to a medicine prepared by using cobra-venom neurotoxin of Elapidae and snake-venom nerve growth factor of Agkistrodon to replace medicine for giving up taking drugs and resisting senile dementia. It is mainly made up by proportionally mixing neurotoxin and nerve growth factor obtained by using cobra-venom of Elapidae and snake-venom of Agkistrodon, passed through such processes of purification, enzyme and gene engineering treatments. The invented medicine can be substituted for medicine for giving up taking drugs, and has better abstinence effect, compared with the existent medicine for giving up taking drugs. Besides, it also can be used for resisting senile dementia, preventing acetylcholine from aggregating inward brain and making intracerebral acetylcholine and dopamine attain metabolic balance.