Abstract: Thunderstorm asthma is a respiratory allergic disease triggered by thunderstorms, which is a global climate-related health event. While its mechanism of thunderstorm asthma is not clear but mainly understood by conjectures up to date. One conjecture emphasizes the increased environmental humidity as a motivation. However, it cannot explain the fact that asthma is not significantly triggered on rainy days without lightning activities. The conjecture that pollen explodes due to lightning discharges lacks experimental verification. To this end, a simulation experiment for suspended pollens struck by lightning was designed with an observation system. Simulated lightning strike tests were carried out with pollens suspended in dry and wet conditions. Through the high-speed photography, scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) measurements, the morphological and characteristic changes of pollens were analyzed after being exposed to lightning discharges. It is found that when pollens are struck by lightning, the ozone and net charges are generated. The particle sizes of pollens decrease, and the surface shapes become irregular. Pollen's wall is penetrated, and the internal substances are exposed. Additionally, carbon and oxygen elements increase on pollen surface after lightning strikes. These findings contribute to understanding the allergenic after struck by lightning in thunder day.