The study of the spatial diffusion and geographical mode of COVID-19 is of great significance for the rational allocation of health resources, the management and response of public health emergencies, and the improvement of public health system in the future. Based on multiple spatio-temporal scale, this paper studied the spatial spreading process of COVID-19 between cities and its evolution characteristics in China, and then explored its influencing factors. The results are shown in the following: the inter-city spreading process of COVID-19 in China mainly experienced six stages, namely, stage I: diffusion in Wuhan, stage II: rapid multi-point diffusion in space, stage III: rapid increase of confirmed cases, stage IV : gradual decrease of new confirmed cases, stage V: the epidemic under control, and stage VI: cases imported from overseas. In the context of globalization and open regional system, the social and economic development of regions are closely related to each other. With the development of fast and convenient high-speed railway network, the spatial characteristic of population migration shows a cross-regional and hierarchical pattern, and forms a certain spatial cascade structure along the transport corridor. Accordingly, the spatial spread of COVID-19 mainly showsthe characteristics of adjacent diffusion, relocation diffusion, hierarchical diffusion, and corridor diffusion. The study found that geographical proximity, population migration and population size, traffic network, epidemic prevention and control measures have significant influence on the spatial diffusion process of COVID-19. Among different modes of transportation, airplanes play agreater role than others in the early stage of the epidemic. In addition, the population flow during the Spring Festival had a certain impact on the spread of the epidemic. In conclusion, to some extent, the spatial spread process and pattern of COVID-19 epidemic reflects the spatial organization pattern of social and economic activities under the "space of flows" network, which is closely related to the geographical proximity, the social and economic linkages between regions, and the spatial an temporal patterns of human activities. From the perspective of geography, this paper analyzed the inter-city spread pattern of COVID-19 epidemic and provided some implications for prevention and control measures against the epidemic in other countries, and also offered some suggestions for China to deal with public health emergency risks in the future.