This paper draws on affective load theory to explore the characteristics of users' affective load in collaborative searching. In this experimental study, a total of 32 participants were recruited and divided into 16 pair‐groups. Each pair‐group collaboratively completed three search tasks in the Coagmento system. Users reported more irritation than anxiety, frustration, and rage. Moreover, the greater a task's perceived difficulty, the higher the irritation, anxiety and frustration felt by users. Users' affective load was higher when they spent more time on a search than they expected to. Conversely, their sense of retrieval success, self‐motivation to search contributed to reducing users' perceived affective load, but not as much as satisfaction with collaborative search results, and satisfaction with collaborative task outcomes did.