Abstract: Special-shaped heat exchange tubes have received extensive attention in the research field of heat exchangers due to their performance advantages such as low flow resistance and good heat transfer efficiency. In order to assist better application of special-shaped tubes in engineering field, numerical simulation method was used to simulate wet gas condensation heat exchange flow field outside the tubes of elliptical tubes, semi elliptical tubes, and flat tubes with six different ellipticities within a certain range of inlet parameters. The variation law of the external condensation heat transfer performance of the special-shaped tube with ellipticity was analyzed by using such parameters as the comprehensive performance parameter J_F and the moisture evolution coefficient ζ. Then, attempts were made to apply three kinds of special-shaped tubes with an ellipticity of 0.5 respectively to a certain circular tube flue gas condenser, and the heat and mass transfer performance of the special-shaped tube flue gas condenser was obtained based on the numerical simulation results. Results show that the comprehensive performance of the three types of special-shaped tube flue gas condensers is better than that of the circular tube flue gas condenser. Among them, the J_F value of the semi elliptical tube flue gas condenser is 10.95% higher than that of the circular tube flue gas condenser, and the ζ is 6.04% higher. Its condensation heat transfer performance is the best.