Abstract: Soil health, reflecting the physical, chemical, and biological properties of the soil is closely related to soil functions and plant productivity. Soil health is crucial for ensuring food security, ecological balance, and human health. Earthworms are known as ecosystem engineers, due to their unique biological characteristics. They are not only indicators of soil health but also play an important role in improving soil health. Earthworms have profound impacts on soil health through their activities such as burrowing, feeding, digesting, excreting, and secreting mucus from their body surface. We reviewed research advances on the roles of earthworms in improving soil structure, accelerating the decomposition of organic matter, increasing soil microbial diversity, promoting nutrient cycling, and providing nutrients for plant growth. Furthermore, we elaborated the role of earthworms in collaborating with their gut microbiota to accelerate the reduction of pollutants in the soil, improve soil purification capacity, maintain ecosystem balance, promote soil health, and increase crop yields. Moreover, we provided an outlook on future researches related to earthworms and soil health.

Key words: earthworm; soil improvement; soil health; ecological function