In recent years, supersonic atomization has become hot topic in novel drainage gas recovery technology for low pressure and low production gas well. But from the field application, the performance is still far from satisfactory. In this study, a Laval tube model and ordinary nozzle model is established using the Fluent software to simulate the flow state of the two models under the same operation condition. Through comparative analysis, this study presents a response to whether the supersonic atomization drainage process can improve drainage effect from mechanical point of view and provides a theoretical decision-making basis for the promotion value of this process. The results show that supersonic atomization facility can truly achieve supersonic state based on the principle of Laval nozzle. There is a significant increase in outlet velocity compared to a normal nozzle. But the effect has very limited range of action and appears to be weak for 1 000~2 000 m well depth.