After the knee is swollen, it is important to determine the extent of the injury, whether it is a simple soft tissue injury or joint ligament injury, or even lead to bone contusion, whether there will be a fracture of a certain part of the knee, and then according to the extent of these specific injuries to do further treatment. If it is just a simple soft tissue injury, it can be treated with cold compresses, then hot compresses and blood circulation and removing blood stasis. Once there is ligament damage, conservative treatment or surgery will be needed depending on the situation. If the knee joint is swollen after a fall and leads to a knee fracture, it is necessary to decide whether to do plaster fixation or surgical treatment according to the fracture alignment.