There are several precautions for mole spotting pen: 1. Spot moles in place and spot cleanly; 2. Disinfect in time after spotting to ensure local inflammation control; 3. Do not operate too many times to prevent the risk of cancer caused by multiple operations. Mole pens can spot moles, often patients buy them and operate them by themselves, so there are not always strict procedures, especially the disinfection procedures, which may cause infection. Mole spotting should be reasonably controlled according to the depth of the mole. If a mole is not spotted cleanly once and repeatedly, too many times may lead to the stimulation of mole cells, and this stimulation is a very important factor to cause local malignant changes.