Abstract: The experimental study on the relationship between the operational parameters and the energy consumption during vacuum freeze-drying was carried out. In this paper, through analyzing the effects of the three main influential parameters, i.e. material thickness, pressure of drying chamber and heating temperature, on the sublimation drying time and energy consumption, the parameters of drying time, energy consumption of sublimation drying curves were obtained under five different levels of the other two. The results indicate that the quadratic law which has apparent consistence exists in the relationships above. In addition, the important sequence of the three factors is as follows: material thickness, heating temperature and pressure of drying chamber on vacuum freeze drying.