Background: In the digital age, fostering young children's computational thinking (CT) and executive functions (EFs) through programming has emerged as a significant research issue. While unplugged programming activities are commonly adopted in preschools, robot programming activities have recently gained attention for the potential to enhance both CT and EFs. Preschoolers are at a pivotal stage for developing CT and EFs. However, there is a dearth of empirical evidence comparing robot programming and unplugged programming activities on preschoolers' CT and EFs development. Therefore, the current research designed a randomized controlled trial to compare the impact of robot programming and unplugged programming activities on 198 5- to 6 year-old preschoolers' CT and EFs (including inhibition, working memory, and cognitive flexibility). Children were randomly allocated to either the robot programming group, the unplugged programming group, or the business-as-usual control group. Results: After a 12-week intervention, results revealed that--(1) the robot programming and unplugged programming groups both outperformed the conventional kindergarten group in CT, with the robot programming group having superior effects in CT over time; (2) the robot programming group outperformed the unplugged programming and conventional kindergarten group on inhibition, working memory, and cognitive flexibility of EFs over time; and (3) most preschoolers in the robot programming group had positive perceptions of programmable robots. Conclusions: The present research demonstrated that robot programming had a more significant and sustained impact on preschoolers' CT and EFs than unplugged programming and conventional kindergarten activities. Accordingly, these findings offered valuable implications for introducing effective programming activities to develop preschoolers' CT and EFs.