Disposable positive-pressure remaining needle

The utility model discloses a disposable positive-pressure remaining needle which comprises a sleeve pipe seat. A piston is arranged in the sleeve pipe seat and is fixed on a push rod, a through hole is formed in the push rod, a clamping position used for preventing the push rod from being pulled out outwards is arranged in the sleeve pipe seat, a spring in the sleeve pipe seat is arranged to make contact with the push rod, interactional force is generated between the sleeve pipe seat and the push rod by the spring, a needle seat outside the push rod is fixedly connected with a needle tubing, the needle tubing is in the through hole of the push rod, penetrates out of the piston and is arranged in a sleeve pipe in a sleeved mode, and a limiting position used for preventing the needle seat from squeezing the push rod is arranged on the needle seat. The disposable positive-pressure remaining needle is simple in structure, convenient to operate, safe and reliable, low in production cost and capable of being widel