Objective To construct a knowledge graph for the Community Nursing course and explore its application effect among nursing undergraduates. Methods A knowledge graph for the Community Nursing course was established through ontology construction，knowledge extraction，knowledge fusion，knowledge storage and visualization. A total of 277 undergraduate nursing students of Grade 2021 from eight classes in a university of Shanxi Province were recruited as the participants. Using a lottery method，138 students from four classes were assigned to the experimental group who received teaching integrated with the knowledge graph，while 139 students from the other four classes received conventional teaching. The course grades and online learning readiness scores of the two groups were compared. Results The constructed knowledge graph for the Community Nursing course contained 715 knowledge nodes，with 186 parent-child relationships，224 prerequisite and post-requisite relationships，and 107 correlation relationships among the nodes. It also integrated 129 teaching materials and 355 self-test questions. The mean completion rate of knowledge points in the experimental group was 98.56%，and the mean mastery rate was 90.65%. The total number of visits to the knowledge graph platform was more than 230 000. The experimental group achieved a mean course score of（85.73±2.87），which was significantly higher than（81.83±2.64） score of the control group（P<0.001）. After the implementation of the teaching，except for the dimension of self-efficacy in online communication，the total score and scores in all other dimensions of online learning readiness in the experimental group were significantly higher than those in the control group（P <0.001）. Additionally，the total score and scores in all dimensions of online learning readiness in the experimental group were higher than those before the implementation of the teaching（P<0.05）. Conclusion Integrating the knowledge graph into the teaching of the Community Nursing course is beneficial for improving students’ course grades and online learning readiness，thereby enhancing the effect of course teaching.