A. Light source using a special ultraviolet lamp, Philips of the Netherlands has high stability, long life; B. Dutch Philips UV lamp specially treated, narrow spectral range UVB311nm pure light source, non-polluting, safe and reliable; C. High irradiation intensity, the treatment effect, the total efficiency of 90% or more; narrow-band UVB the lightwave treatment of superiority: 1, a short course of treatment, the effect of fast and total efficiency of 90% or more; 2, without taking other auxiliary drugs, avoid the use of photosensitive drug side effects; effective light output intensity the matte side effects, there is a good safety and tolerability, no significant effect on normal skin; recurrence after cure than single drug therapy better. 4, to avoid the the traditional long wave of PUVA and wide-band UVB may cause skin burns and carcinogenic chance.