Negative acetic acid test and negative iodine test are terms commonly used in colposcopy. A negative acetic acid test result means that a thicker white acetic acid epithelium does not occur when the cervical epithelium is recoated with acetic acid, so it is negative, which means good. If the iodine test appears negative, which means that there is no local staining of the cervix during the iodine test, this is a negative result. Under normal circumstances, it should be a positive result. The said positive result means that the cervical area will be completely blocked after applying the dot, but a negative result does not mean that there is a lesion. If mustard yellow appears in the iodine coating, it means that local lesions may occur, and often the mustard yellow tissue will be taken and sent for pathological examination, and the final pathological diagnosis will prevail.