Tourism city brand image construction is a strategic measure to enhance the city’s core competitiveness, and has received great attention from various tourism cities. As a new force in promoting urban development, local youth must accurately grasp their perception of the city’s brand image, to realize the simultaneous development of youth development and urban development, and the integrated development of youth, industry, and city. This paper focuses on the city brand building of tourist cities among local youth, adopts the brand association measurement tool “brand concept map”, takes Chongqing, a tourist city in China, as the field, and the local youth as the research object, and establishes the analysis perspective of the correlation strength of results based on traditional methods. Based on exploring the characteristics of brand image perception, this paper further explores the formation mechanism behind the characteristics from the perspective of the diversity of local youth’s perception channels of city brand image.