Abstract: In the context of a new round of information technology development, the application of GaAs pseudomorphic high electron mobility transistors in RF communication deserves attention. The article summarizes the main degradation mechanisms of their I-V characteristics and proposes the direction and measures for performance optimization. The article analyzes the layer structure and function of transistors, derives the I-V characteristic equation of transistors, establishes the mapping relationship between device physical level parameters and circuit level parameters, and seeks the degradation law of performance parameters such as threshold voltage, leakage source current, and transconductance. In order to provide a clear description of the performance degradation process, the article divides the main degradation failure mechanisms into three aspects: structural defects, thermal stress, and environmental factors. In order to alleviate the degree of degradation and failure of transistors, this article explores the space for performance improvement and optimization approaches from the aspects of structural materials, processing technology, and circuit design.