Supracondylar humerus fracture wearing Kirschner’s pins is generally the operative procedure for fractures in children, and fixation usually requires cast immobilization for 4 weeks after fixation, and then the Kirschner’s pins are removed to begin functional exercises. Cross fixation with two Kirschner’s pins is the fixation method for cut-and-replace internal fixation of supracondylar humerus fractures. Postoperatively, the affected limb needs to be immobilized in a position of 90° of elbow flexion with a plaster cast. Functional exercises of clenching fist, flexing and extending fingers and wrist joints can be performed in the early stage, which is helpful to reduce edema. Generally, supracondylar humerus fracture Kirschner’s pin in children is stable, and functional exercises of the elbow joint can be performed as early as 4 weeks postoperatively, which helps to preserve the normal function of the elbow joint. In addition, since the end of the Kirschner pin will be exposed about 0.5cm into a hook shape after the operation, it is also necessary to do a good job of sterilizing the exposed part of the Kirschner pin to prevent infection. Also be careful not to touch water to avoid infection.