A smart city provides a new idea and model for urban construction, management, and development. This article proposes the concepts and methodology for top-level design of smart cities based on the“Integration of Four Plans”, and the planning process and systems for implementing the top-level design of smart cities. This article discusses, from the perspective of a city, how to optimize resource allocation, coordinate the development of urban economy, society, resources, environment, and people’s livelihood, and map out the blueprints for healthy and sustainable development of a smart city.