Cholinesterase is a glycoprotein that can generally be divided into true cholinesterase and pseudocholinesterase. All clinical references are to the true cholinesterase, also called acetylcholinesterase. The measurement of cholinesterase is of clinical significance. Generally, increased levels are seen in the presence of neurological disorders, hyperthyroidism, diabetes, hypertension, etc. Decreases can be seen with organophosphorus poisoning, hepatitis, cirrhosis, malnutrition, etc. The determination of cholinesterase activity in clinical practice is mainly to help diagnose and differential diagnosis of organophosphorus poisoning. In patients with organophosphorus poisoning, serum cholinesterase activity is reduced, and the degree of reduction is proportional to the degree of poisoning, which can guide treatment and assess the efficacy of treatment and prognosis, and is therefore a very important indicator of organophosphorus poisoning.