Objective: In order to achieve rapid detection of methyl parathion. Methods: An acetylcholinesterase sensor was prepared based on gold nanoparticles and reduced graphene oxide for quantitative detection of Methyl parathion. Reduced graphene oxide, gold nanoparticles and acetylcholinesterase were successively modified on the surface of the screen printing electrode by layer-by-layer assembly method. The catalytic activity and impedance characteristics of the sensor, the relationship between the sensor's inhibition rate and MP concentration, and the actual sample detection were evaluated. Results: The prepared acetylcholinesterase biosensors showed excellent affinity for acetylthiocholine chloride with the Michaelis-Menten constant of 2.76 mmol/L. Under the optimal conditions, Methylparathion could be effectively detected with a linear range of 5 ng/mL to 500 ng/mL and a detection limit of 0.692 ng/mL. Conclusion: The method is simple, practical and stable. It provides a reliable method for rapid detection of organophosphorus pesticides.