Abstract: In this study, a numerical model for calculating the smoke generation rate of e-cigarettes is proposed. The model accounts for the energy loss due to the evaporation of e-liquid on the atomizer surface and the heat released from the smoke condensation on the walls of the external airflow channel. The evaporation rate of the e-liquid on the surface of the atomizer and the condensation rate of smoke on the walls of the airflow channel are obtained through Fick's law. The effects of atomizer geometry and heating mode on the smoke generation rate are investigated with the proposed model. Results show that when all surfaces of the heating section are heated, the smoke generation rates of grooved atomizers and cylinder atomizers are comparable, both exceeding than that of cuboid atomizers. However, after optimizing the heating surface arrangement, the smoke generation rate of the grooved atomizers exceed that of cylinder atomizers. These findings provide a reference for the optimization design of e-cigarette atomizers. In addition, the modeling method and the results of this study can also serve as a reference for the optimization design of other heat-vaporization atomizers, such as medical thermal vaporizers.