This empirical research aims to propose and examine an online teaching approach that embeds modeling-eliciting activities (MEA). The approach guides teachers to create a well-interactive online learning environment and improve the conceptual learning and professional skills of engineering undergraduates. The professional skills are defined as critical thinking and collaboration. A structured teaching procedure was implemented sequentially by task introduction, problem description, performance analysis, structural optimization, and solution discussion. The six principles of MEA were organically integrated with the teaching procedure, creating a inspiring, open-ended, and teamwork learning environment. The instruments used to collect data included conceptual learning tests, design report evaluations, learning reflection analyses, and interaction statistics. The findings suggested that the MEAembedded online courses have significant advantages for improving learners' conceptual learning and professional skills. The proposed approach guides the learners to make appropriate decisions and practical actions, enhancing their critical thinking. The MEA inspires learners' positive attitudes and high participation, providing an emotional basis for group collaboration. The discussions on the open topics and thought process reflections create a collaborative environment. Besides, the statistics on the online teaching platform show that the MEA has a significant role for interaction promotion in the online course.