The new salt-tolerant alfalfa variety of Zhong Clover No. 3 is based on the salt-tolerant and high-yielding materials from Zhong Clover No. 1 and crossed with each other, and then obtained the new salt-tolerant alfalfa variety through three rounds of selection based on one mixed selection on saline land with a salt content of 0.21%-0.46%. It was validated by the National Grass Variety Validation Committee in 2006 and registered as a bred variety. The new variety has the advantages of salt tolerance, high yield and fast regeneration. On the saline land with salt content of 0.18%-0.39% in Huanghua, Hebe, and the yield is 12.6% higher than the control variety Zhong Clover No.1. On saline land with soil salinity of 0.21%-0.37% in Nanpi, Hebei, the hay yield was 10.8%-12.7% higher than that of Zhong Clover 1. On saline land with soil salinity of 0.21%-0.39% in Zhongjie farm in Hebei, the yield was 10.4% higher than that of Zhong Clover No. 1, and its hay yield under rainfed conditions reached 1019.7 kg/mu on average for three years period. This variety is suitable for planting in large saline areas and low-yielding fields in the Yellow Huaihai region, and can also be planted in other inland saline lands in China. The scale of Zhongclover No. 3 alfalfa promotion and planting has been expanding, and by the end of 2022. It has been planted on a large scale in 10 provinces and regions, including Inner Mongolia, Hebei, Shandong, Ningxia and Shanxi.