<p>Social media is an important way for people to search for tourism information, and the quality of tourism information has also attracted attention. However, there are few studies on how to attract overseas tourists to travel. To uncover the internal relationship between tourism information quality and travel intention, this study draws on the heuristic-systematic model and the theory of planned behavior. Using partial least squares structural equation modeling (PLS-SEM), the study analyzes data from 460 respondents who had viewed Portugal tourism information on social media. The research finds that partial content quality and non-content quality, respectively, influence tourists’ affective and cognitive country image through systematic and heuristic processing models. The two jointly prompt tourists to form a positive attitude towards Portugal, thereby significantly enhancing their travel intention. Meanwhile, attitude, subjective norm, and perceived behavioral control also have a positive impact on travel intention. This study not only reveals the mechanism of the effect of tourism information quality on overseas travel intention, enriches the application of the heuristic-systematic model in the tourism field, but also further expands the theory of planned behavior. In addition, this study provides incisive insights for the destination, which helps marketing agencies optimize tourism information on social media platforms and offers a scientific basis for attracting overseas tourists to travel to Portugal.</p>