Abstract: The large-scale atmospheric LNG tank is a very important unit equipment in LNG terminal, and its cooling process is the highest risk link and is the most difficult to be controlled in the commissioning and test run process of LNG terminal. In this paper, the cooling process preconditions and precautions of LNG storage tanks in the commissioning and test run process of LNG terminals are introduced in detail, and the relations between technical parameters in the cooling process, such as temperature trend, the trial operation of the LNG terminal, tank temperature trends, spray cooling flow rate, cooling rate and maximum temperature difference in monitoring point in LNG storage tank during the cooling process are analyzed and discussed. It is pointed out that in the cooling process the problems such as pipeline's deformation to blockage, leaking at pipe flange connection, uneven temperature decrease of the storage tank due to uneven cooling rate control, and liquid accumulation in flare system, etc. will easily occur. Relative measures against these problems are given. The research results can provide a reference to the cooling of LNG storage tank in the commissioning and test run process of other LNG terminals.