Dr. Dong-Gang Wang obtained master degree in the Department of Astronomy, USTC in 2016, and obtained doctoral degree at Leiden University in 2020. Now he is a postdoctoral researcher inthe Stephen Hawking Center for Theoretical Cosmology at the University of Cambridge. Hisresearch focuses on the observational tests of high energy physics during cosmic inflation.Cosmic inflation, as the leading paradigm of the early Universe cosmology, also serves as a natural laboratory with extremely high energy. Therefore with the help of cosmological observations, inflation offers a unique opportunity to test new physics effects in the primordial Universe. In this talk I will introduce one particularly important observational channel — primordial non-Gaussianity, which encodes a large amount of information, and is expected to play an important role in futuristic astronomical experiments. I will give a stateof-art review concerning both theories and observations. At the theoretical frontier, the latest advances in effective field theory and cosmological bootstrap allow us to uniquely determine the modelindependent signatures of new physics. From the observational perspective, the large scale structure and 21cm surveys will largely boost the chances of detecting these primordial signals, and may lead to exciting discoveries in the near future.