Spartina alterniflora is one of the typical invasive alien species along the coast of China. This species has formed a large-scale invasive population in Dafeng Port, Yancheng, Jiangsu. This study set up a total of 9 mowing+shading and only mowing plots in Dafeng Port and analyzed the differences of influences on the upper part and underground rhizomes of S. alterniflora among different control technologies and different lengths of shading time. We further monitored the control effect of S. alterniflora and the impact on soil nitrogen and phosphorus content and macrobenthos after removing the shading net. To explore the shortest shading time required to effectively control Spartina alterniflora. The results showed that the two control technologies extremely significantly reduced the plant height, base diameter, density, and fresh weight of the aboveground plant of S. alterniflora (P<0.01). After mowing+shading was implemented for 3, 6, 9, and 12 months, the shading net was removed in turn, the aboveground part of S. alterniflora disappeared completely, and did not re-grow at the vigorous growth period of the second year. Both of the two control techniques significantly reduced the survival rates of the rhizomes of S. alterniflora (P<0.05). And there was no significant difference among the effects of different control technologies and different lengths of shading time on the survival rate of rhizomes. After removing the shading net, the biomass of macrobenthos increased significantly (P<0.05), but the soil nitrogen and phosphorus content did not change significantly. This study found that removing the shading net after 3 months of mowing+shading control technology in Dafeng Port, Yancheng, Jiangsu Province, is the most efficient prevention and control method for treating Spartina alterniflora and the restoration of native species.