Based on the edX platform, this paper designs the knowledge graph model by combining expert method and reference method, selects Neo4j as the knowledge storage database of knowledge graph; selects Echarts as the visualization tool of Neo4j, and finally realizes the visual search and display of knowledge points on MOOC platform, and gives learning feedback and update according to the learning situation of learners. When planning the learning path through the designed knowledge graph, Ripplenet algorithm is introduced to enrich the diversity of courses in the learning path planning between courses. Professional learning path planning is provided for learners to improve the learning efficiency of online learning.