Abstract: For the LNG tank,Controlling the evaporation rate of BOG resulting from heat release and pressure of BOG (internal pressure of LNG tank) is of importance to the safe operation of LNG receiving terminal.By analyzing the process of heat response for the fluid in LNG tank,a mathematic model for the fluid is established.The dynamic simulation analysis on heat load of LNG tank,the influence of release rate of BOG to evaporation and pressure of BOG is carried out,and suggestions controlling the evaporation and release rate of BOG are put forward as well.