Abstract: Insect chitinases can degrade chitin in the insect body wall and peritrophic membrane, thus playing a crucial role in insect molting and other life activities. Among the key enzymes involved in the chitin degradation system of insects, group II chitinase (ChtII) is a specific enzyme with multiple domains and complex functions. Silencing of the gene encoding ChtII in insects can lead to molting failure and increased mortality. The analysis of the biochemical properties and crystal structure of ChtII indicates its "pioneering and tackled" role in the chitin degradation system. Thus, ChtII is expected to be a new target for insecticides. This paper reviews recent progress on the physiological function, structural characteristics, and inhibitors of ChtII, aiming to provide insights for the creation of green pesticides based on insect chitinases.