Abstract: To solve the problem of high energy consumption and high cost of oil tank during its running, temperature filed model of oiltank is simplified to carry out numerical simulation Distribution of temperature field is obtained under the condition of two dimension unstable state heat conduction, and then analysis on energy consumption of insulators of tank wall and/or tank top and process of oil tanker loading as well is made. Taking realizing energy saving and energy consumption reduction as an objective, feasibility of installing insulator on double-roof of tank is demonstrated Optimized technical parameters in insulator thickness of tank wall, insulator location of floating roof and oil loading temperature of oil tanker etc. are obtained through calculation.