The cyclic corrosion tests for different coating systems were carried out by thehorizontal square tube and the vertical tube simulation equipment respectively. The corrosionresistance performance of different coatings under insulation was evaluated，and the test methods of square tube and vertical tube were compared and discussed. The results showedthat common phenolic epoxy coatings，glass flake reinforced phenolic epoxy coatings and inertinorganic copolymer coatings exhibited excellent corrosion resistance. However，the coatingsystems containing the silicone aluminum powder failed the test due to their poor dry filmthickness. Besides，compared with the vertical tube test，the test conditions of the square tube were more severe，therefore showing a better screening performance for different coatings.