Based on the Conservation of Resource Theory, this paper constructs a regulated intermediary model, and empirically studies the influence of workplace loneliness on employee helping behavior. The results show that workplace loneliness has a negative impact on employee helping behavior, and relational identity plays an intermediary role between workplace loneliness and employee helping behavior. Self-control resource depletion negatively regulates the relationship between relational identity and employee helping behavior, and self-control resource depletion regulates the intermediary role of relational identity between workplace loneliness and employee helping behavior. Therefore, enterprises should pay attention to workplace loneliness and strengthen management, and take corresponding incentive measures to encourage employees to improve relational identity and supplement self-control resources, so as to reduce the negative impact of workplace loneliness on enterprises.