In order to solve the problems of uneven glue application during the spraying of lap glue in high-speed machines, the glue application process was simulated by Fluent, and the changes of glue outlet viscosity and outlet flow rate were observed by changing the inlet pressure of the nozzle. Firstly, Solid Works was used to model the lap glue nozzle, then Fluent was analyzed to simulate the lap glue spraying and gluing process, and finally the adhesive performance, including initial viscosity and T-peel resistance, was analyzed in detail by experimental tests under different inlet pressure conditions. The simulation results show that the outlet viscosity of the nozzle gradually decreases with the increasing in inlet pressure, while the outlet flow rate is just the opposite, i.e., it increases with the increasing in outlet pressure. The two adhesive properties of the outlet glue under the difference of the inlet pressure also differ, mainly in that the apparent viscosity of the outlet of the lap nozzle decreases with the increase of the inlet pressure, resulting in a certain degree of reduction of its adhesive properties. The fluid simulation of lap gum spraying is useful for the optimization of cigarette production process.