STEM (Science, Technology, Engineering, and Mathematics) education is attracting increasing attention, but how to improve students' STEM learning achievement is still a big challenge. In the process of learning, students actively set learning goals, organize learning content, set learning standards, and independently adapt learning strategies and monitoring measures in order to achieve their own learning goals and to help them learn STEM knowledge and skills. Concept mapping is considered to be an effective visualized knowledge organizing tool that helps students to manage and organize their knowledge systematically and visually. This study proposes a concept mapping-based self-regulated learning approach. A quasi-experiment was conducted using a concept mapping-based self-regulated learning system in order to evaluate the effectiveness of the approach. The experimental results show that the proposed approach significantly improved students' STEM skills, but not their STEM knowledge compared to the conventional self-regulated learning approach. The proposed learning approach helped to improve students' self-regulation compared to the conventional self-regulation learning approach. In short, the concept mapping-based self-regulation learning approach enhances students' self-efficacy and self-regulation, which in turn helps students to learn STEM skills effectively.