Nowadays, the society is highly intelligent, and smart city has become the common expectation of people. Smart city is a large concept, which includes smart home, Smart Transportation, Smart public, Service and Social management, smart Urban Management and other aspects. This paper mainly discusses the problem of the mobility in cities. The mobility in cities can be divided into two categories in practice, namely, the movement of humans and the movement of goods. In this paper, we enumerate the typical cases in the mobility of humans and goods, and analyze the operation principle of these cases one by one. Some of these examples are implemented, some are not. In order to make urban mobility "smart", we propose a framework of assistive system, which has a four-tier structure and uses big data, cloud computing, AI, deep learning and other technologies. It is aimed at a variety of different scenes, to provide users with the most thoughtful advice and the most humanized service, to solve the problem of urban mobility