The learner-centered concept has become an important trend in educational field; collaborative learning is exactly the realization of such a concept. Many studies have pointed out that collaborative learning is better than traditional competitive and personal learning. However, there still exist some practical issues while applying collaborative learning, groupthink is one of them. Although researchers have developed many mechanisms for solving the practical issues of collaborative learning, groupthink can not be eliminated effectively. Because of groupthink, learning groups may jump to coherent conclusions quickly before a fully knowledge sharing and constructing process is being executed. This is against the spirit of Social Constructionism which is the essential theory of collaborative learning and reduces the benefits of collaborative leaning. Learning process control is an effective mechanism for reducing the groupthink effect. However, learning process control mechanism usually cannot work as expected because of the inappropriate guide of instructors or different leading styles of group leaders. Therefore, the aim of this study is to develop a system with the support of learning process control mechanism using mobile devices is developed to ensure the mechanism will be properly executed. The results show that self-censorship, which is one of the symptoms of groupthink, can be reduced significantly if learning process control mechanism is executed on mobile devices compared to the execution on traditional worksheets. Moreover, the groups using mobile devices support for executing the learning process control, the four symptoms of groupthink can be greatly reduced compared to the groups without any learning process control and learners could have better learning attitude and interactive level. Therefore, this study proved that groupthink can be reduced by having learning process control mechanism executed on mobile devices. Finally, some future research topics are proposed based on the research results.