Acetylcholinesterase（AChE） has been widely used for the detection of organophosphate and carbamate pesticides. In this work， the CpAChE gene has been constructed to match P. pastoris-preferred codon usage for simple scale-up fermentation. We have analyzed the characterization of CpAChE and evaluate the application effect in pesticide residue detection. Meanwhile， the computer simulation technique was used to investigate carbofuran-binding amino acid residues of CpAChE. The results showed that the codon-optimized recombinase CpAChE activity was 7.4 U/mL （increasing 40-fold）. The optimum temperature and pH value for activity are 25 ℃ and pH 8.0， respectively. The kinetic parameters of CpAChE are found to be Km of 1.639 mg/mL， and Vmax of 8.071 μmol/min/mg， respectively. The inhibitory effects of most organic reagents on the enzyme activity were examined. By contrast， the activity of the enzyme is strongly activated by Mg2+， K+， Ca2+ and Li+. When Mg2+ （5 mmol/L） was added to the enzyme， it is obvious that a 1.7-fold increase in the activity of the enzyme can be seen. The recombinant CpAChE showed high sensitivity to organophosphorus and carbamate pesticides， and the detection limit of carbofuran was 0.044 μg/mL. The results of molecular docking indicate that the carbofuran and the 19 amino acids of recombinase CpAChE were tightly bound by the hydrogen bond network and hydrophobic interaction， and the Tyr146， Ser147 and Tyr355 are likely to play a more important role. In conclusion， the optimized CpAChE gene is a high-level expression. Meanwhile， the mechanism between the recombinant CpAChE and carbofuran were investigated. This work provides theoretical support for the application and molecular evolution of the CpAChE.