The application discloses a lens and its button adjustment structure. The button adjustment structure includes a connecting seat, a guidepost, a base and an elastic member. The connecting seat is fixedly connected to the lens or may be part of the lens. The connecting seat includes a first gear structure. The guidepost is fixed on a fixed member on one side of the connecting seat. The base is movably sleeved on the guidepost along an axial direction of the guidepost. The base includes a second gear structure. The elastic member is sleeved on an outer periphery of the guidepost and is located between the base and the fixed member. An elastic force of the elastic member drives the second gear structure on the base to engage the first gear structure of the connecting seat.