A field pilot–scale experiment was conducted to evaluate the comprehensive effects of nitrification inhibitor CP application on wheat grain yield, nitrogen usage efficiency (NUE), nitrous oxide (N₂O) emission and ammonia (NH₃) volatilization from soil under different N applied rates. Results showed that CP application significantly increased wheat grain yield by 17.8% and 15.4% when N applied rates were 140 kg/hm² and 180 kg/hm², respectively. Furthermore, the NUE of wheat was increased by 11.3%-25.2% under CP added treatments. The application of CP decreased N₂O emission rates (especially during the observed periods after basal and earing fertilizers applied) and thereby reduced wheat seasonal cumulative N₂O emissions by 39.3%-53.7%. However, the total NH₃ volatilization of wheat season observed under CP added treatments were 1.46-1.75 folds of that observed under their counter treatments without CP, which were mainly observed during the monitoring periods of basal and earing fertilization. We conclude that the CP application can promote the NUE of wheat, thereby enhance wheat grain yield, and reduce N₂O emission, whereas lead to higher NH₃ losses at a certain degree, thus should be controlled.