With the development of the concept of Process-Based Therapy (PBT), Process-Based Behavior Therapy (PBBT) has emerged as a concrete intervention method. Rooted in the latest developments of Relational Frame Theory (RFT), PBBT provides a comprehensive and clear perspective for clinical intervention and case conceptualization by analyzing an individual’s psychological processes across multiple levels and dimensions. The therapy divides self-relating into three layers: the Manifest Layer, the Character Layer, and the Essence Layer, while also analyzing the S+ (strengthening) and S- (avoidance) functions at each level. This offers a multi-dimensional approach to clinical interventions. This article details the theoretical basis, key concepts, and essential components of PBBT, compares it with other therapeutic approaches, and highlights its unique features. Additionally, through a clinical case study, the application of PBBT in treating social anxiety disorder is illustrated. By analyzing self-relating patterns and functional responses, PBBT helps patients effectively reduce anxiety symptoms, improve social skills, and enhance overall quality of life.