Phubbing, which is a kind of social exclusion, refers to the phenomenon that individuals ignoring offline social interaction for using mobile phones. It is a byproduct of the mobile phone and has potential threats to users' relationships and mental health. The research on phubbing mostly focuses on interactions between partners. Mobile phones play an important role in maintaining and promoting intimate relationships. There is an evidence that the use of mobile phones for relationship maintenance (e.g., daily texting) increases communication between partners, commitment and relationship satisfaction. However, inappropriate use of mobile phones can also be disruptive to individuals or couples, resulting in less time to spent together, more conflicts, lack of emotional support, and less intimacy. Based on the analysis of the structure of partner phubbing, this paper further analyzed its impact. From the perspective of the function of the family system, the influence of the phubbing behavior is divided into two aspects: one is for the impact on the individual mental health of the phubbee ignored by his/her companion(s) in a social situation because his/her companion(s) uses or check their smartphones; the other is about the impact on the romantic relationship between the two partners. Most studies have shown that partner phubbing can lead to negative emotional responses in phubbees. It can also weaken the relationship between partners and undermine the quality of intimate relationships. Furthermore, phubbing can also affect individual mental health by damaging romantic relationships between partners. In addition, this paper explained the theoretical mechanism of partner's phubbing behavior from the perspectives of expectancy violations theory, social exchange theory and interdependence theory. The expectancy violations theory starts from the individual's expectation of others and analyzes the behavior of partner's phubbing. It suggests that a partner expects to receive whole-hearted attention. However, phubbing violates such expectation and thus brings negative interpersonal relationship impact. Social exchange theory emphasizes fair exchange in interpersonal communication, and holds that maintaining a good relationship requires partners to balance their efforts and rewards. If this balance is broken, it will have a negative impact on the development of the relationship. When one is left out because of phubbing, the imbalance between efforts and rewards will lead to a decrease in relationship satisfaction, causing conflicts and other problems. Interdependence theory focuses on the interactive process of interpersonal interaction and holds that the emotion, cognition or behavior of the partners will affect each other. When phubbing takes place between partners, such negative experience will reduce the relationship satisfaction of the phubbee and increase negative emotions. The negative feedback of the phubbee will also affect the behaviors and feelings of the phubber, so the two sides are prone to frequent conflicts. In general, based on the existing research, the research in future can take the following two aspects into consideration: exploring cross-relationship (romantic relationship to parent-child relationship) and the mechanism of the effect of partner phubbing on intimate relationship. The mechanism also includes revealing how partner's phubbing behavior works (intermediary mechanism), finding protective factors (regulatory mechanism), and intervention program.