Pro-skinny women usually have poor breast development, thin chest wall muscles, tight breast skin and limited stretching ability. The size (base diameter), capacity and shape of the prosthesis directly affect the surgical effect, so it is necessary to avoid breast stiffness and fullness. Too many prostheses will cause asymmetric breast deformation, and the prosthesis will move down, resulting in "bottom puncture" deformity of the lower pole of the breast. The diameter of the prosthesis should not be wider than the existing diameter, which is enough for implantation. When thin people use physiological saline prosthesis for breast augmentation, anatomical prosthesis can also obtain satisfactory results.