Disposable IV needles as the name suggests are disposable and can only be used for short-term or single use because the needle is a steel needle, so it can not be retained in the blood vessels for a longer period of time. The patient’s slightest activity can easily cause the needle to puncture the blood vessel resulting in extravasation of the medication. The medication needs to be removed immediately at the end of the infusion and should be re-punctured next time if the infusion is still needed. The needle that is pulled out is not allowed to be punctured again because it has been contaminated, and the needle should be replaced if puncture is still needed. There are requirements on the infusion fluid, corrosive drugs and irritating drugs should not be infused. Once the liquid enters the tissues outside the vein, especially the corrosive drug extravasation, it will cause phlebitis in the light case and tissue necrosis in the heavy case. Infusion into the liquid or drug with little irritation, now clinically there is an indwelling needle can be retained for 3 days to reduce the pain of repeated puncture, the needle is soft, to reduce the post-puncture activities or other circumstances, resulting in needle penetration of the blood vessels, causing extravasation of the drug occurs, so clinically it is now generally recommended to use the indwelling needle.