Abstract: In order to ensure the density of smoke in the bulk curing barn and reduce the energy consumption of baking, a variable volume system suitable for the bulk curing barn was developed. After the design of the variable volume device was completed, the influence of different distances between the device and tobacco leaves on the uniformity of gas distribution inside the bulk cuing barn was simulated and analyzed based on the CFD method. The actual roasting data was obtained through the roasting test, and the simulated values were verified. The test results showed that when the distance between the separator and the tobacco leaf was 0 cm, the non-uniform coefficient of flow velocity Kv was 0.40, the non-uniform coefficient of temperature Kt was 0.41, Kv=0.41, Kt=0.43 when the distanc was 10 cm, Kv=0.42, Kt=0.49 when the distanc was 20 cm. The simulated temperature values of 9 measurement points in the cigarette loading area were basically consistent with the measured values, with an error of within 6%. When the capacity of the variable volume curing barn was half, the fuel consumption can be saved by 13.4% compared to the conventional curing room. The research results indicated that when the distance between the partition and the tobacco leaves was 0 cm, the gas distribution inside the curing room was the most uniform. The CFD model and numerical simulation results had a certain degree of reliability. The variable volume device has good insulation effects, which can ensure the density of tobacco loading and reduce energy consumption of flue-cured tobacco.