The development of smartphones packed with applications has brought great convenience to, and improved the quality of, people’s daily lives, but it has also changed people’s behavior. People spend more and more time on mobile phones every day, leaving them distracted, affecting their sleep quality, and thereby giving rise to the concept of smartphone addiction. As a major group of smartphone users, college students have also experienced situations in which the use of mobile phones has decreased their learning efficiency as they try to escape from academic pressure. This article presents quantitative research on college students in Halmstad and aims to explore the connection between smartphone addiction and interaction anxiousness. Data was collected from a sample of 123 smartphone-using college students using an incidental sampling method; questionnaires provided a scale to rate smartphone addiction and interaction anxiousness. Statistical Product and Service Solutions (SPSS) 23 was used to analyse descriptive statistics, Pearson correlation, independent-sample t-test, and regression and so on.  According to the results, smartphone addiction is not common among college students. The overall status of college students’ interaction anxiousness is close to a moderate level. Levels of interaction anxiousness varied significantly depending upon gender, subject and grade. There is a significant positive correlation between smartphone addiction and interaction anxiousness. Interaction anxiousness has a certain predictive effect on smartphone addiction.