The world economic growth further slowed in 2016 as well as employment growth. The prices of commodities kept in low-middle band after rebound and global inflation increased lightly. International trade and investment have been depressed since 2012. Global outstanding debt has been rising continuously and international financial market fluctuated frequently. There are many challenges facing world economy，which include falling global potential economic growth rate，more fragile financial market，instability caused by the change of U.S. policies，low growth of international trade and investment，more inequality of income，and more serious anti-globalization. These challenges will restrain the strong，sustainable，balanced and inclusive growth of world economy. Moreover，geopolitical risks，refugee crisis，political cycle of great powers and terrorism may bring negative effects on the stability and development of world economy. It is expected that the PPP-based GDP growth rate of the world economy is 3.0% in 2017.