The teaching materials of vocational colleges has two categories: the chapter-based and task-based. The former, stressing too much on the integrity of knowledge structure is lack of skill training, while the latter, stressing too much on working process is incomplete as it splits the theoretical knowledge. Taking The Equipment Maintenance of Railway Mobile Communication System (GSM-R) as an example, a teaching material is written by combining the chapters and the tasks with the structure of “background knowledge
link of key points”. It highlights the training of practical skills and the reasoning of “subject knowledge system”.