The work aims to clarify the internal relationship between city brand and city image, and apply the city brand positioning theories to the visual identity design of city marketing events. Through data collection and analysis, the city brand positioning coordinate system based on city image data was constructed following the principles of city brand positioning to provide a theoretical basis for city brand positioning decision-making. The city image labels of Shenzhen were extracted and the city brand positioning strategies were proposed from the perspectives of Built Environment, Vitality Degree, Development Environment, Livable Degree:modern and fashionable landscape for garden city, young and diverse culture for creative city, tolerant and innovative gene for immigrant city and green and environmental ecology for livable city. At the same time, the corresponding visual identity design proposals of city brand were put forward. By finding the position of the city image labels in the city brand positioning coordinate system, the comprehensive competitiveness of the city can be positioned, thus providing design strategies for the creation and promotion of city brand image.