Objective To explore the characteristics of online learning behavior of nursing undergraduates，clarify their learning style，and provide theoretical support for improving the effectiveness of online teaching. Methods The learning data of 284 nursing undergraduates who participated in the online course of Nursing English from September 2020 to December 2022 were collected. The K-means algorithm was used to conduct clustering and visualization analysis on the characteristics of online learning behaviors，and the relationship between online learning behaviors and learning effect was explored by combining the data differences in the performance of learning behaviors of different categories of learners. Results The learning behaviors of nursing undergraduates in the Nursing English online course were relatively positive. The learning styles were predominantly conformist（32.39%，92/284） and moderate（45.42%，129/284），with fewer independent（14.79%，42/284） and repulsive（7.39%，21/284） learners. The differences in the learning behavior performance of nursing undergraduates with different learning styles were statistically significant in terms of the total scores，the time of task published until submission，the number of discussions，the number of questions answered and the video regurgitation ratio（P<0.05）. Conclusion Nursing undergraduates hold different learning style preferences. Independent and conformist learners preferred self-directed and guided learning styles，respectively. Meanwhile，moderate learners displayed no obvious style preference，and the repulsive learners showed more negative performance in all learning behaviors. Nursing educators and relevant departments of educational administration should take learning style preferences as a reference in design targeted teaching and learning activities and to develop academic early warning system，in order to improve teaching and learning effect.
