Black marks after acne may be caused by melanin deposition after acne inflammation, which can be improved through general treatment, medication, physical therapy and other ways. 1. General treatment: patients should pay attention to skin care, keep the affected skin clean and dry, avoid rubbing and squeezing the acne marks to avoid infection, prevent ultraviolet radiation, do a good job of sunscreen, and consume foods with high content of vitamin C, such as oranges, grapefruit and lemon. 2. Medication: patients with black acne marks can follow the doctor’s instructions to use topical medications, such as cumulonimbus cream ointment, fruit acid cream, polysulfonic acid mucopolysaccharide cream, vitamin A cream and other topical treatments to improve the symptoms of black acne marks. 3. Physical therapy: patients can also be treated with laser therapy, photon therapy, radio frequency microneedle therapy, etc. to promote pigmentation and improve the condition. It is recommended that patients consult the doctor in a timely manner, strictly follow the doctor’s instructions for medication, actively cooperate with the doctor’s treatment, and do a good job of monitoring the condition.