The product uses a small oil-free silent compressor as an air source. By charging the gas into the liquid nitrogen container, the liquid nitrogen discharged from the container is achieved. The product is hermetically sealed by the upper and lower flanges and the silicone gasket. Nitrogen removal operation can be carried out with the special flange of the nitrogen removing device at the neck of the liquid nitrogen container. The nitrogen discharge rate can be adjusted according to the exhaust pressure adjustment knob. The container and the nitrogen collector are connected by a quick joint, so that the installation and disassembly are convenient. The utility model is suitable for taking liquid nitrogen liquid from liquid nitrogen containers frequently.