The United Nations 2030 Sustainable Development Goals (SDGs) involve society, economy, and environment, and the Belt and Road Initiative (BRI) is an important path to implement the SDGs. Moreover, the BRI is a vision for economic development of countries along the route. Although many studies documented the effect of the BRI on environment and economic performance, few studies have discussed the effect of the BRI on social and economic benefits. Therefore, we introduce the public health expenditure to explore the relationship between the BRI and the public health and economic growth of countries along the route from the dual perspective of social development and economic growth. Based on a panel data from 171 countries from 2010 to 2018, the current research explores whether the BRI can boost public health and promote economic growth in the belt-road countries. As a result, we found that the BRI boosted the expenditure of public health and effectively spurred economic growth in the belt-road countries. Furthermore, the effect of the BRI on the economic growth in the countries along the route depends on the level of public health expenditure in each country; the positive effect of the BRI on economic growth is significant when the public health expenditure level is moderate instead of low or high. The findings provide theoretical and practical insights into the SDGs of the BRI.