My mom had laser hair removal therapy after that her face is full of scraches .now what is cure? is it safe to continue therapy

Laser may itch: I am not sure if you are asking if the laser caused the scratches ( unlikely) or made her itchy which promoted her to scratch herself (more likely)"laser may cause histamine release and inflammation which can be itchy. Pretreatment with antihistamines and post treatment with Hydrocortisone cream may help.

Try a new technician: Laser hair removal, like any other laser treatment can cause injury to the surrounding skin. Usually this is just temporary irritation that recedes on its own. Use adequate moisturizer and stay out of the sun do not have more treatment until it has resolved. You might want to try a different laser or perhaps a different practitioner.