After the knee is bruised to see if there is skin trauma, if there is a wound need to go to the hospital in a timely manner, usually local need to use saline for flushing, and then to see if there is the presence of foreign closed eyes, according to the situation for further stitches or tetanus injection, etc., at the same time need to check whether there is a fracture of the knee area. If there is no surface wound but the knee is bruised, ice can be applied to the knee within 24 hours to prevent local vasoconstriction and excessive bruising. After 2-3 days of icing, hot compresses can be applied to accelerate local blood circulation and help dissipate the bruising.