<p>Amid increasing complexity in scientific problems, accelerated knowledge turnover, and the growing intensity of interdisciplinary integration, researchers are exhibiting a rising tendency to dynamically switch across research topics. Despite its prevalence, the cognitive antecedents and underlying mechanisms driving topic switching behavior remain theoretically underexplored and empirically underexamined. Drawing on cognitive search processes, this study employs a scholar-year panel dataset encompassing 25,241 computer science scholars to examine how different dimensions of cognitive search influence topic switching. The results demonstrate that cognitive search variation positively predicts topic switching probability, whereas cognitive search effort shows a negative association. Importantly, these two dimensions interact in a complementary effect: under conditions of higher cognitive effort, broader exploratory search more effectively facilitates transitions across research topics. Moreover, career length positively moderates this complementary relationship, underscoring the amplifying role of career development in translating cognitive strategies into behavioral outcomes. This study offers a systematic account of the cognitive search mechanisms underlying topic switching behavior, thereby contributing to the advancement of cognitive perspectives in the study of scientific careers, particularly in the field of computer science.</p>