The invention discloses a student modeling and personalized course recommendation method in an 
online learning system, and belongs to the education 
data mining field. According to the method, 
cognitive level modeling and personalized course recommendation of students are mainly studied, firstly, knowledge mastering states of the students are judged based on a 
cognitive diagnosis model, learning behaviors of the students are analyzed through data on a 
system platform, and then the cognitive abilities of the students are modeled by integrating course mastering conditions; secondly, an 
online course is modeled ; and finally, the features of the 
online course are fused according to the 
cognitive level of the student to perform personalized recommendation. According to the invention, personalized recommendation is carried out based on the 
cognitive level of students and in combination with the feature indexes of the online courses, so that the user can be helped to carry out more accurate personalized course recommendation, and the 
online course recommendation is more interpretable and acceptable.