Androgenic alopecia（AGA），also termed as seborrheic alopecia，is the most common type of clinical alopecia，and the hair follicle miniaturization acts as a main clinical manifestation of AGA. Currently it has been considered that many reasons can induce hair follicle miniaturization. On the one hand，they promote dermal papilla cells of scalp hair follicle to secrete hair follicle inhibitory factor，and to have apoptosis and autophagy disorder；on the other hand，they destroy microvasculature surrounding the dermal papilla，and also cause depletion and fibrosis of hair follicle stem cells and dermal sheath cells，eventually causing the gradual transition from the initial terminal hair to thin pili. This review discusses the update mechanism of hair follicle miniaturization resulting from distinct type of hair negative factors and holds substantial promise for the future treatment of AGA.