Human development is in an infinite process, but the development of city is in a limited space. The three-dimensionalization of urban buildings and the three-dimensionalization of urban traffic correspond to each other. To solve the problem of three-dimensional traffic in cities, car elevators have come to life from a dream. Car elevator is a special elevator that solves the problem of vertical transportation of cars. Its standard load is 3000KG, 5000KG. The speed is 0.25-0.5m / S. As an important vehicle vertical transportation tool, compared with traditional car ramps, car elevators can save 80% of the building area and more than double the car turnover efficiency.