White powder after dry urine may be urine salt crystals, may also be caused by urinary tract infection. Urine salt crystals because of low water intake, high temperature environment so that water evaporation in the body, urine pH changes lead to body water loss, the urine crystal material concentration or solubility of the increase or decrease, triggered by the concentration of urine, generating urinary salt crystals. Urine salt crystals are generally small, easy with the urine out of the body, usually after the urine is dry, the performance of white powder, generally by drinking more water can be improved. If the urine is dry with white powder, and at the same time the urine foam increases, the emergence of urinary urgency, urinary frequency, urinary pain and other symptoms, then consider that it is caused by urinary tract infections. Treatment is generally recommended to use antibiotics as prescribed by the doctor, such as macrolides, cephalosporins and quinolones, commonly used are levofloxacin, cefuroxime and so on. In addition to medication, drink more water and flush the urethra more often to eliminate inflammation. Diet should be light, avoid spicy and stimulating food, and pay attention to urethral hygiene.