The operation of ultrasound-guided central venous catheterization generally includes six steps: positioning, confirming venous patency, real-time ultrasound-guided venous puncture, confirming that the puncture needle is located in the venous vessel, confirming that the guidewire is located in the venous vessel, and confirming that the central venous catheter is located in the venous vessel, which are as follows: 1. The first step is to identify the anatomical structure of the puncture site and locate the position of the vein, identify other anatomical structures related to the determination of arteries and veins, and check for anatomical variations. 2. Immediately following to confirm the patency of the vein, generally using ultrasound probe compression method to determine the presence of venous thrombosis, color Doppler imaging can confirm the patency of the vein and the size of the blood flow. 3. The third step is to perform real-time ultrasound-guided venipuncture asepsis, using ultrasound to continuously observe the tip of the puncture needle as it approaches and penetrates the vein. 4. Confirm that the puncture needle is located in the venous vasculature, and make sure that the tip of the puncture needle is in the center of the vein before placing the guidewire. 5. Confirm that the guidewire is located in the venous vasculature. Be sure to confirm that the guidewire is in the correct position. 6. Confirm that the central venous catheter is located in the venous vessel. After confirming that there is no error, ultrasound-guided central venous catheterization is completed.