Disclosed is a biometric information acquisition system and a processing method thereof. The biometric information acquisition system comprises a transparent substrate; a light source; a photoelectric conversion device, which is located at one side of the transparent substrate with the light source, receives light reflected by the transparent substrate and generates electrical signals; a processing device for obtaining biometric information based on the electrical signals. At least a portion of the transparent substrate is made of flexible material, and fits a predetermined portion of an organism on the other side of the transparent substrate based on a curved interface, therefore, ambient light incident to the photoelectric conversion device is reduced, an interference caused by the ambient light is reduced, accuracy of acquiring biometric characteristic information is improved. Because fitting with the curved interface can increase contact area, more biometric characteristic information of the predetermined portion can be obtained.