The steps of knee cast immobilization include the following steps: 1. Preparation. 2. immobilization. 3. adjustment of position. 4. handing over the precautions for cast immobilization. Firstly, the length as well as the width of the limb should be measured, the plaster bandage should be prepared, and the number of plaster bandages to be used should be estimated if tubular plaster fixation is to be adopted. Secondly, after the preparation, the plaster is immersed in water and fixed accordingly, and if the fixation is a plaster cast, a bandage is taken to wrap and fix it. If it is to take tube type plaster fixation, to take plaster bandage binding, wrapping and fixation. When the plaster is not fully cured, the position of the limb should be adjusted, including the angle of knee flexion and extension, and after adjusting the position, the position should be kept unchanged until the initial curing of the plaster, which usually takes 5-10 minutes. After the cast is cured, it will have initial strength, and the patient can go home to recuperate or return to the ward to continue treatment without weight bearing. At the same time, we also need to explain the precautions of plaster fixation, such as whether there is localized pressure, whether too loose, whether too tight, explain the time of regular follow-up, explain the problems to be carried out at any time to consult the doctor, generally is the above process.