We investigated the relationship between snubbing a peer in favor of using a cell phone (phubbing) and mobile game addiction by introducing avatar identification as a mediator, and feelings of social exclusion and perception of belonging as moderators. Participants were 530 Chinese mobile game users who completed a survey comprising measures of peer phubbing, avatar identification, feelings of social exclusion, perception of belonging, and mobile game addiction. Results were as follows: (a) peer phubbing affected mobile game addiction through avatar identification; (b) feelings of social exclusion moderated the relationship between peer phubbing and avatar identification, and the mediating role of avatar identification in this link; and (c) perception of belonging was linked to the relationship between peer phubbing and feelings of social exclusion, affecting avatar identification and the mediating role of avatar identification in this link. Our results demonstrate the impact mechanism of peer phubbing on mobile game addiction and provide a new perspective on mobile game addiction prevention.