This report summarizes the development status and problems faced by small and medium-sized cities. Under the background of the new era，it is of great strategic significance to explore the path and strategy of green development of small and medium-sized cities. This report aims at three typical modes of green development of small and medium-sized cities：tourism，resource and agriculture. Taking Jinggangshan，Shangri La，Erlianhot，horingol，Longjing and Golmud as examples，this report analyzes the practices and paths of green development of small and medium-sized cities，and summarizes the key path of taking small and medium-sized cities as regional unit carriers to realize the construction of a beautiful China.