The precautions after photorejuvenation include timely cold compresses, moisturizing and sun protection, and adjusting living habits. 1. Timely cold compress: after photorejuvenation, the skin may have short-term redness, swelling, pain and other adverse reactions. Immediately after the treatment, you should use aseptic mask or cold film to apply cold compresses to lower the temperature of the skin surface and reduce the symptoms of skin erythema and edema. 2. Moisturizing and sunscreen: After photorejuvenation, the physiological barrier of the skin has not been fully established, and it is recommended to use milder skincare products, and try to use medical grade skincare products. Pay attention to daily skin cleaning, timely hydration and moisturizing. When you go out, use sunscreen plus physical sunscreen to avoid sunburn. 3. Adjustment of living habits: after photorejuvenation, attention should be paid to avoid hard friction skin, do not recommend eating spicy stimulating food, sauna, avoid strenuous exercise in the short term, because these factors will affect the repair and reconstruction of the skin barrier after treatment, affecting the effect of hydrazine injection. It is recommended to pay attention to scientific care after photorejuvenation, if there is any discomfort, please go to the hospital immediately.