The LNG sampling system is a special sampling product developed based on the characteristics of LNG. It is mainly used in LNG receiving stations. LNG production plants sample from LNG transmission pipelines. The basic principle is that ultra-low temperature media such as LNG are first injected through the "vacuum vaporization integrated probe". During the sampling process, LNG and other low-temperature media enter the check valve through the cryogenic stop valve in the probe, enter the vaporizer, and enter the system after vaporization. . The cryogenic cutoff part and the vaporizer part of the probe are both vacuum insulated. The pressure and temperature of the vaporizer used can be adjusted. The temperature can be adjusted in time according to the set temperature control device. The pressure adjustment range is 0~250psi; the buffer tank Its function is to uniformly mix the heated sample gas and serve as buffer and storage. The sample gas mixed in the buffer tank will be discharged to the exhaust gas recovery system or flare through N2, so that the system reaches a circulation state. After the pressure in the buffer tank reaches a certain level, the unloading valve opens to release the pressure to prevent the continuously vaporized sample gas from accumulating high pressure and damaging the system.