A broken knee needs to be treated according to the extent of the injury. If only a slight abrasion of the epidermis of the knee occurs, you can directly disinfect the local area with iodophor, or you can use Bactrim to apply the local area, keep the local area clean and dry, and avoid getting wet to prevent bacterial infection from occurring. If the local trauma is more serious, the wound is larger, the wound is deeper and bleeding is more, you need to use hydrogen peroxide for local debridement and disinfection, suture the wound if necessary, and follow up to keep the wound clean and dry. Take oral antibiotics to avoid local bacterial infection, such as cephalosporin antibiotics, and tetanus antitoxin injection to avoid tetanus infection. If the knee joint is impacted by external force and joint swelling and restricted movement occurs, it is necessary to go to the hospital to rule out the possibility of fracture by photographing.