The invention belongs to the technical field of pasture planting, and particularly relates to an after-culture method suitable for Tibetan heavy-degraded grassland. The method includes that after-culture is performed on the Tibetan heavy-degraded grassland before rainy seasons come, and the specific time is from middle April to late May; poa crymophila keng, Siberian wildrye, awnless brome and wheatgrass are selected as after-culture varieties; manual broadcast sowing or mechanical sowing-in-drill is adopted for sowing. The after-culture method can effectively increase forage grass yield of the Tibetan heavy-degraded grassland, increase forage grass supply rate, expand Tibetan livestock forage grass source, increase income of farmers and herdsmen, improve living standard of the farmers andthe herdsmen, relieve natural grassland pressure and reduce grassland ecological degradation and damage.