As a matter of fact, the observation of high energy cosmic ray always plays a crucial role in astrophysics investigation, which can infer the processes happened in universe, e.g., the supernova burst, black hole merger. In recent years, PeV-scale gamma photons has been firstly observed by human beings, which marks a new step for cosmology study. With this in mind, this study will analyze the observation as well as mechanism for the generation of such extremely high energy gamma rays. To be specific, this study will first introduce the state-of-art observation tools for high energy particles. Subsequently, the advanced observation results will be demonstrated at the same time. Based on the results, the possible mechanisms will be presented in the meantime. Moreover, according to the analysis, the current defects and drawbacks of the observation as well as theorem will be discussed. Overall, these results shed light on guiding further exploration of high energy particles analysis.