Abstract: As the equipment deployed for storage and transportation of low-temperature fluids, the low-temperature storage tanks shall be well performed in thermal insulation for necessity of economy and safety. In accordance with principles of thermal insulation through external osmosis, an innovative low-temperature storage tank with thermal insulation through external osmosis structure is developed. The structure can enhance the insulation performance of the low-temperature storage tank by gas evaporation generated within the tank to penetrate permeable materials on sidewalls of the tank. A heattransfer model is established to calculate volumes of heat transfer through top, sidewalls and bottom of the storage tank. The results show that, compared with conventional storage tanks, the innovative storage tank with external osmosis structure can reduce 60.7% of heat transferred through sidewalls, and total heat losses and daily evaporation reduced by 22.2%. In summary, thermal insulation performance of the storage tank can be improved significantly.