Objective: In view of the lack of small continuous walnut drying equipment in the market, a small walnut belt continuous dryer was designed. Methods: Based on the theory of gas-solid heat transfer, the heat fluid solid coupling model in the drying device was established, and the two-dimensional and three-dimensional simulation analysis was carried out with fluent to obtain the distribution and change law of gas temperature field in the drying device and walnut temperature field; By changing the top of the drying chamker from flat top to 30°, build a drying test platform for drying test, compare the test data with the simulation results, and verify the effectiveness of the model. Results: The design of walnut belt continuous dryer with a maximum drying capacity of 360 kg/h was completed. After simulation and optimization, the spatial distribution of pressure field and temperature field in the drying room was more uniform, the eddy current between the layers of drying medium field disappeared, the temperature difference between the boundary and the internal center of the drying room was very small, and the temperature distribution was more uniform. Conclusion: Optimizing the structure of the drying device can significantly improve the distribution of flow field and temperature field and improve the drying effect.