Cognitive diagnosis is the application of cognitive analysis in teaching. On the basis of the problem-solving cognitive process analysis and cognitive simulation discussed in Chaps. 4 and 5 , we propose the following to deepen the understanding cognitive operations and cognitive components in the process of problem solving and to explore the cognitive process of “one-on-one” cognitive diagnosis on the basis of a cognitive model. Specifically, more detailed and more targeted guidance and advice for educational practice and individual development can be provided to students, especially those with learning difficulties.