After opening the cap, the iodophor does not wait for it to expire and then stop using it in order to ensure the disinfection effect as well as the principle of sterility. Usually about 3-5 days, it needs to be replaced. Povidone-iodine is a commonly used disinfectant with a broad-spectrum bactericidal effect, killing bacterial propagules, fungi, protozoa and some viruses. It is an indeterminate conjugate of monomeric iodine and polyvinylpyrrolidone. The concentration of medical povidone iodine is generally less than 1%, and the color appears as light brown. In clinical work, each time a bottle of povidone iodine is opened, the corresponding time will be recorded. In order to ensure the disinfection effect as well as the principle of sterility, povidone iodine is usually replaced in about 3~5 days according to the use of povidone iodine. If the patient needs to use povidone-iodine, it is recommended to go to the hospital, to clarify the specific situation of the current lesion area, and then use it under the guidance of the doctor, to ensure the disinfection effect of povidone-iodine, and also to ensure the smooth recovery of the lesion area.