Abstract Visitors’ recognition of the Expo has a direct impact on its reputation and value. Based on the theory of relationship marketing, this study analyzes the impact of food and agricultural Expo’s service quality on visitors’ relationship quality and relationship continuity intention, and clarifies the mediating role of relationship quality. Out of 660 questionnaires distributed to visitors with food and agricultural Expo experience in China, 600 valid questionnaires were collected for data analysis. We use SPSS 26.0 to make an empirical analysis of the collected data and use structural equation modeling to propose the relationship between potential variables. The results show that organizational service, facility service and digital service, which constitute service quality, have a significant positive impact on visitors’ relationship quality, but the impact of operational services on visitors’ satisfaction is not significant. The four dimensions of service quality all have a positive impact on relationship continuity intention. The empirical results of satisfaction and trust in relationship quality have a positive impact on the relationship continuity intention. All these results demonstrate the overall characteristics of China’s food and agricultural Exposition market and help to provide practical data for future marketing strategies.