Abstract: Low carbon-nitrogen ratio (C/N) often leads to insufficient biological denitrification and nitrate accumulation in wastewater treatment process. As a kind of agricultural waste, corncob has many advantages, such as low cost, a wide range of sources and good biodegradability. Notably, the carbon release amount of corncob can be improved after proper treatment. Hence, corncob has a certain application potential in the field of wastewater treatment. This paper summarized the research progress of carbon release process, influencing factors, pretreatment methods, and the application of corncob in the treatment wastewater with low C/N. In order to improve the extensive resource utilization of corncob, some proposals were suggested, including accurate dose of corncob in bioreactor, combination of corncob with other materials, the impact and mechanism of other impurity ions on corncob carbon release process, environmentally friendly corncob pretreatment chemicals, the application of corncob in mariculture wastewater treatment, and the mechanism of biofilm formed on the surface of corncob.