Objectives: This study aimed to provide the measures for improving the self-directed learning ability and the reference data for substantializing the educational programs by verifying the main factors affecting the self-directed learning ability of dental hygiene students in reality when the learners' autonomy is emphasized than ever. Methods: From June 20 to July 4, 2022, an online survey was conducted targeting total 218 dental hygiene students. The collected data was analyzed by using the SPSS Program Version 22.0. Results: First, in the results of analyzing differences in detailed items of self-directed learning ability according to the general characteristics, the 'students who entered the department of dental hygiene by considering their aptitude and interest' showed higher results than the 'students who entered the department by considering their high school record'. Second, when the academic efficacy, study immersion, and problem-solving ability of dental hygiene students were higher, their self-directed learning ability was also high. Third, the factor that had the greatest effect on self-directed learning ability of dental hygiene students was problem-solving ability, which was followed by academic efficacy and study immersion. Conclusion: Putting together the results above, in order to cultivate the problem-solving ability of dental hygiene students, it would be necessary to operate the problem-solving-centered simulation course that could foster critical thinking, interactions with others, and creative approach and solution to problems in dental medical site. It would be also possible to improve their academic efficacy by applying the learning mentoring & one-to-one learning counseling program, and also strengthening proper feedbacks for learners. Moreover, the study immersion could be strengthened by developing and operating the emotion-based learning motivation program & learning coaching program through the process of verifying the potential and growth needs of learners, exploring one's own resources through learning diagnosis/introspection, and exploring the career-related vision for strengthening the learning motivation, which could have positive effects on the improvement of self-directed learning ability.