The small gas phase liquid nitrogen tank realizes real-time temperature monitoring, liquid level monitoring, automatic replenishment, remote monitoring and alarming, and automatic backup storage of monitoring data. Based on the capacitive liquid level sensor, the liquid level can be easily and automatically controlled to achieve gas-phase storage at -190°C at the top of the tank, which completely solves the technical problems of electronic information technology in the low temperature environment of -196°C. The advanced liquid nitrogen tank manufacturing technology and intelligent monitoring technology are perfectly combined. The product is light in weight, small in footprint, large in capacity, and efficient in sample access. It can monitor the running status of the liquid nitrogen tank in real time, and alarm in time if there is a problem to ensure that the sample Store safely. Mainly suitable for users such as biomedical and sample libraries.