Abstract: In gas filling stations, pressure differential level gauge is often used to measure the level of low-temperature LNG tank, which, however, fails to provide accurate results. In this case, actual stock and loss of LNG can not be estimated rationally and accurately, to say nothing of corresponding LNG stock and loss management. In order to address huge error in measurement due to the pressure surge and change of liquid saturation state when LNG tank is used, principles and components of several level gauges which adapt to low-temperature LNG medium are presented. Common types of probes, installation of devices and precautions are discussed. Advantages and disadvantages of such gauges are compared. Finally, the optimized scheme of installation of servo-level gauge on LNG tank is put forward, which can achieve the accurate measurement and safe operation of LGN tank, thereby removing the difficulties in measuring low-temperature tanks in gas filling stations.