1, the treatment of drugs on the skin mucous membrane cells infected by HPV virus has a high degree of selectivity; 2, non-toxic, harmless and non-invasive; 3, the only one on the HPV subclinical infection and warts at the same time with the role of smelting therapy; 4, photodynamic therapy has a low recurrence rate of only 5 to 10%. The recurrence rate of the other is 30-40%; 5, the urethral opening, urethra, cervix, rectum or anal canal warts and other special parts of the treatment can not be effectively treated; 6, no scar formation after treatment, will not cause urethral stenosis, adhesion, is the first choice of treatment of urethral opening, within the warts (other physical, chemical methods, such as CO2 laser, ghost toxin are prone to produce urethral adhesions) (other physical and chemical methods such as CO2 laser and onychomycin are prone to produce urethral adhesions, strictures, leading to dysfunction after treatment).