To evaluate the seasonal dynamic effects of Pinus massoniana vegetation restoration on soil N₂O emissions and nitrogen leaching losses in red soil erosion regions in southern China, this study focused on different stages of vegetation recovery (bare land, 10, 20, and 30-year-old Pinus massoniana plantations, and natural secondary forest) in typical red soil erosion areas in Changting County, Fujian Province. Field devices for collecting soil leachate solutions were used to monitor NH+ 4-N and NO₃^--N leaching losses in different forest soils. Laboratory incubation methods were also employed to observe the seasonal dynamic characteristics of N₂O emissions. The results showed that soil inorganic N leaching was mainly in the form of soil NH+ 4-N in forest land at different vegetation restoration years, while NO₃^--N was the main form in the natural forest. Moreover, the leaching losses of NH₄⁺-N and NO₃^--N tended to increase with increasing vegetation restoration years. N₂O was mainly absorbed by forest soils across different vegetation restoration stages, and the N₂O emission rate was positively correlated with soil net nitrification, net ammonification and net N mineralization rates. N₂O absorption by various forest soils showed an increasing trend with increasing recovery years. These findings indicated that vegetation restoration in southern red soil erosion areas reduced gaseous nitrogen (N₂O) losses, but the leaching loss of NH₄⁺-N and NO₃^--N was not effectively reduced by vegetation recovery. In the future, it should continue to strengthen the protection and sustainable construction of forest vegetation, avoid excessive artificial exploitation and destruction, and gradually restore the water and fertilizer conservation function of forest areas.