The mechanism of dandruff production is mainly the disruption of the ecological balance of the scalp. In fact, a healthy scalp is maintained by three major balances, the balance of oil, flora and metabolism. When the dandruff secretion of the scalp is out of balance, the scalp will become oily and greasy. When the environment of scalp flora is out of balance, harmful flora will proliferate, which will lead to itchy scalp symptoms. And the scalp’s cuticle metabolizes too quickly and sheds, which results in dandruff. As an important head barrier of the human body, the scalp is second only to the eyelids in terms of vulnerability and sensitivity, so it can be said that one hair will move the whole body, so the scalp should get attention when there is a problem. The most abundant bacterial species on the scalp would be Propionibacterium and Staphylococcus. These two species inhibit the balance of each other while influencing the balance of dandruff. If a certain imbalance is disrupted, the dandruff generation mechanism is disturbed, so dandruff increases. It may also be related to diseases such as psoriasis.