Urbanization synchronized with economic development is called active urbanization (also called healthy urbanization). On the contrary, urbanization before the level of economic development is called pseudo-urbanization or over-urbanization, which often leads to a series of problems, such as excessive population pouring into cities, excessive burden on urban infrastructure, insufficient employment in cities and so on. Urbanization that lags behind the needs of economic development level is low urbanization, which often leads to a series of problems such as uncoordinated urban industrial development, insufficient urban service capacity and insufficient rural labor transfer. Excessive urbanization and low urbanization belong to negative urbanization (also called morbid urbanization).