China’s urban transformation since 1978 is notable for both its scale and speed. Focusing on the dimension of speed, we propose the concept of the ‘urban speed machine’ to assess its role in shaping the politics and political economy of Chinese urbanization. We argue that in China speed must not be understood merely by means of measurable outcomes of change, but rather that speed is an essential and vital element embedded within China’s specific processes and mechanisms driving urban growth. In this sense, speed is constantly at the forefront of local cadres’ considerations, since moving fast to achieve urban growth is an expression of political imperatives and pervasive city‐based accumulation strategies. The Chinese urban speed machine, as we conceive it, mainly involves three state‐dominated institutional arenas: the Communist party’s personnel review system, the planning mechanism and local finance. We also discuss regional variability vis‐à‐vis the nature of speed in urbanization and in the differing responses to problems of fast‐city growth in recent years. This article’s core contributions are to clarify the paramount importance of speed in the political economy of urban growth and illuminate a relational understanding of the politics of speed in China’s urban change.