Abstract: As the largest developing country, China feeds 22% of the world’s population with 10% of the world’s total arable land. We must pay attention to the issue of food security due to China’s food supply is tightly balanced. In order to reduce the pressure on food supplying, we choose Melilotus officinalis as herbage. Equivalent calculation is made to compare protein, amino acid, fat and polysaccharide content between food nutrition content and herbage nutrition content. On the other hand, soil samples of planting beginning and ending are collected to compare soil physical and chemical characteristics values. The results are as follows, crude protein content of Melilotus officinalis reaches 17.5% of fresh weight and nutrition proportion is reasonable. It can replace food crops, replacement rate reach to 35%. Beside this, salt, alkali content, pH value and sodium ion exchange rate of soil that had planted Melilotus officinalis decrease significantly, content of soil organic matter and total nitrogen increased significantly. Therefore, developing forage protein is an available way to improve the level of food security in China, and soil environment has non-toxic pollution and has obvious improvement effect.