In the process of drying chrysanthemum, the flow field distribution in the dryer was the main factor affecting its quality. In order to further study the distribution and variation of flow field in the drying process of chrysanthemum, a physical model of the drier was established for the negative pressure dryer. The distribution of velocity field, pressure field and temperature field in the drying process of chrysanthemum were obtained by mesh division, parameter determination and calculation. The numerical simulation of flow field distribution in the drying process of chrysanthemum was realized. In order to verify the accuracy of the simulation results, the simulation results of the temperature field and the measured results were compared and analyzed, and the relative error was found to be within 8%, which fully confirmed the reliability of the simulation results.