The purpose of this study is to investigate the effect of instructional consultation on strengthening teaching competencies of professors by providing them with instructional consultation according to the degree of participation. The main research problem is to clarify the effect of instructional consultation in universities on professors’ awareness of lecture problems, lecture design, and lecture practice in detail. For this, instructional consultation was conducted for 24 university professors throughout a semester. Specifically, the instructional consultation was divided into different areas such as professors, subjects of lecture, and students, and self-reports, recording materials, and students’ satisfaction were analyzed. Additionally, problems to be improved were drawn based on the evaluation results of teaching approaches according to the degree of participation of instructional consultation, and the structure of lecture was divided into introduction, development, and conclusion to analyze the details by each stage, based on which advanced teaching strategy was suggested. As a result of the action research, it was revealed that instructional consultation had positive effects on some components of professors’ teaching competencies such as self-examination of their own lecture, cooperation with fellow professors, lecture design and practice, and restructuring of lecture. Furthermore, instructional consultation in universities helped professors face their own lecture and realize its problems, and advanced alternatives for lecture design and practice were explored through self-examination according to the realization of problems and cooperative interaction with consultants. In addition, anxiety about recording the lecture and skepticism felt during the process of planning and practicing lecture turned into confidence after going through cooperative interaction with consultants. Based on the results, the efforts of the professors who participated in the instructional consultation to improve their own lecture had positive effects on strengthening their teaching competencies.