Abstract: The lung is an important part of the human respiratory system, and the airway epithelium is the first barrier between the lung and the external. It is involved in defending against foreign particles, pathogens, etc, expelling foreign bodies as sputum and plays a vital role in maintaining the normal function of the respiratory tract. Commonly used in vitro cell culture models and mammalian models cannot fully simulate the human lung-airway microenvironment yet, and have limitations in the study of human cellpathogen interactions and drug development. In this research, we designed a microfluidic chip by improving the preparation process to meet the requirements of very short working distance of high magnification microscope for high-resolution imaging. The lung-on-a-chip reproduced the air-liquid interface airway epithelial culture, simulated human lung-airway microenvironment and obtained real-time observation of the co-culture process of cells and bacteria. It provides a powerful research platform for studying the interaction between airway epithelium and pathogenic microorganisms in vitro.