The utility model provides a seedling culture box for afforestation in severe regions. The seedling culture box comprises a box body which is internally provided with a cavity, a bottom plate of the box body is provided with through holes, a movable top cover is arranged at the top of the box body, and the box body comprises an inner wall, an outer wall and a filling layer arranged between the inner wall and the outer wall. The seedling culture box is characterized in that through holes are arranged in the inner wall of the box body at intervals and communicated with the filling layer, and a water-retaining agent and slow release fertilizer are placed in the filling layer. The water-retaining agent and the slow release fertilizer placed in the filling layer are utilized fully in the gradual degradation process of the box body, sufficient nutrient content is provided for plantlets continuously, meanwhile, sufficient moisture is kept, the plantlets can have enough growth time through the seedling culture box, and high survival rate and preserving rate is ensured. The seedling culture box can be used for afforestation and vegetation restoration as soon as possible in regions, with severe conditions, such as high-mountain cold and wet regions, Karst regions, high-latitude high-humidity low-temperature regions and mine waste regions.