This application provides a lens module and a lens module control method to implement, among other features, automatic focusing and improve image definition. The lens module includes an imaging lens, a first control module, a first processing module, a liquid lens, and an image chip. The liquid lens is configured to refract an imaging beam that comes from the imaging lens, and the liquid lens comprises a transparent first flat lens and a transparent second flat lens that are parallel to each other. The first control module is configured to adjust a distance between the first flat lens and the second flat lens. The first processing module is configured to adjust a distance between the first flat lens and the second flat lens by using the first control module and based on a definition of the digital image, so as to adjust the definition of the image generated by the image chip.