Shanghai Ninth Hospital Mohe Road can make frozen liquid nitrogen. Shanghai Ninth Hospital is a regular dermatology hospital. Liquid nitrogen cryotherapy can be done in the dermatology department of a regular hospital. If there are spots or pigmented nevus on the skin surface, it may affect the beauty of the skin. Doing liquid nitrogen cryotherapy can achieve better therapeutic effect. However, when doing liquid nitrogen cryotherapy, it is necessary to choose a regular hospital to ensure the therapeutic effect and reduce the damage to the skin, and it is necessary to strictly follow the doctor's advice after operation.