Abstract: In view of the process in the gas gathering station, establish a calculation model of pressure drop. Total pressure drop is divided into three parts: pressure drop from gas nozzle throttling to transmission valve (which is obtained by the statistical method), pressure drop of gas nozzle throttling (which is determined by the combined throttling theory and statistics), and pressure rise of heater (which is derived by the constant volume gas state equation). By a calculation example and error comparison, the practicability and reliability of the model is proved. With this model, the relationship between the input pressure of single well and the output pressure in the gas gathering station can be obtained accurately. Thus, the single-well production variation under different transmission pressures can be predicted.