Abstract: Drying is an important means of agricultural products during storage processing. Hot air drying is widely used in industry because of its low cost, high efficiency, sustainable mass drying and so on. The hot air drying involves complex heat and mass transfer process which is closely related to the development of green and energy-saving drying process and equipment. In this paper, three kinds of numerical simulation methods of heat and mass transfer in hot air drying are reviewed, namely, drying dynamics model, continuum hypothesis model and pore network model. The basic theories and research status of the numerical simulation methods, merits and demerits, and application of prospects in drying are summarized.