The fixation method of the indwelling needle is generally divided into 4 steps, such as holding the film for fixation, pressing for molding, pressing while tearing the border, and smoothing the dressing. 1. Holding membrane fixation: after successful puncture, the film should be held without tension and fixed with the puncture point as the center, and then smoothed to both sides to avoid tension damage. 2. Pressing and molding: gently pinch the protruding part of the catheter connector and the isolation plug, start pressing from the base of the needle and gradually move upward, so as to make full adhesion between the dressing and the connector, the isolation plug as well as the skin. 3. Pressing while tearing off the border: It is necessary to press to the whole dressing to make the dressing in full contact with the skin, and then tear off the border on the film while pressing the edges of the dressing. 4. Smoothing the dressing: after tearing off the border, start from the center, gradually smooth to both sides, press the edge part to make the whole dressing fully bonded with the skin. Improper fixation of the indwelling needle may lead to catheter dislodgement, bleeding at the puncture site, etc. It cannot be fixed at home by oneself, and should be carried out in the hospital under the standard operation of professional doctors.