Lignite is the most potential alternative energy source in the future. Due to its porous structure and spray dust reduction during the mining process, the lignite has a high moisture content, which leads to an increase in the energy consumption of dry distillation. Drying can effectively dewater it and improve the grade. In this paper, the dehydration and upgrading of wet low-grade lignite using a multi-layer reverse cross-flow drying bed were researched. The focus was on the change trend of the dehydration rate of the lignite in different beds. The distribution law of moisture content in the drying bed and the different drying function periods were determined and systematically analyzed. The influence of parameters such as drying temperature and smoke-coal ratio on drying characteristics was explored, at the same time, the significant influence of drying parameters on drying effect was analyzed and the optimal operating parameters were obtained (Rsc = 7.6, T = 200℃, t = 20 min). The test results show that: when the drying time t = 0-5 min, it is the fast drying period, and when t = 5-10 min, it is the constant-velocity drying period, and when t = 15-20 min, it is the slow drying period. When t = 10-15 min, it is accelerated drying period. With the increase of smoke-coal ratio (Rso), the dehydration rate of lignite increases first and then decreases. When the smoke-coal ratio Rsc = 7.6, the dehydration rate of lignite reaches the maximum value of ηcoal = 88.99%, and the dehydration effect is better at this time. After drying, the wet lignite has a moisture content of 2.95% and an ash content of 12.78%. The dehydration range of lignite of various density grades is obvious, realizing the efficient dehydration and upgrading of low-grade lignite. [ABSTRACT FROM AUTHOR]