Non-suicidal self-injury (NSSI) refers to intentionally harming one's own body tissue without intending to die or cause injury to others. Common forms of NSSI include cutting, burning, scratching, hitting oneself, and pulling out hair. There are various etiology for NSSI behaviour, which ranges from that of emotional dysregulation to those of cognitive factors. We are particularly interested in the development of a Cognition-Emotion-Behaviour model of NSSI. However, there exist various states concerning cognition (713 functions), emotion (558 states), and NSSI behaviors (81 ones), according to the well-known medical terminologies SNOMED CT. It is non-trivial to know which cognition functions and which emotion states would lead to which kinds of NSSI behaviours. In this paper, we propose a Cognition-Emotion-Behaviour model of NSSI by using an approach of Knowledge Graphs with semantic analysis on the literature mining of NSSI. We will show how cognition, emotion, and NSSI behaviours can be explored by using this knowledge graph approach.