Under the background of Guangdong-Hong Kong-Macao Greater Bay Area，high-speed rail can connect the “9+2” cities more closely，which is conducive to form a synergistic development pattern of complementary advantages，co-construction and sharing. Establishing the concept of regional synergetic is critical to the development of the economics of high-speed rail；innovation synergy mechanism is the basic guarantee for promoting high-speed rail city linkage；leveraging high-speed rail is expected to achieve a leap in regional industrial status. The basic effect of the economics of high-speed rail is the deepening of regional division. High-speed rail promotes polarized development of regional service industry market，which is conducive to large manufacturing headquarters in developed cities；and the industrial spillover in the core area is an important opportunity for the new high-speed railway zone. The general path of the economics of high-speed rail is to gather popularity first and then achieve production：gathering popularity is an important goal in the first stage of development；and industrial space is the core content in the second stage of development；major events are a powerful impetus for the rise of urban status. The conditions for the development of the Economics of high-speed rail are traffic interconnection. Improving traffic micro-circulation is conducive to enhancing the attractiveness of high-speed rail，and promoting air-rail linkage can expand the influence of high-speed rail.