A strategy by multi-objective genetic algorithm (MOGA) combined with Kriging response surface is proposed for optimum design of wavy fin tube in an air cooler, while minimum pressure loss factor, maximum heat transfer factor and overall performance factor as three objective functions. The results show that the effects of fin height and fin density on the overall performance are positive and the wave number and wave angle are negative; The overall performance of parallel fin is higher than staggered fin; The overall performance of small pipe diameter of wave fin is higher than big pipe diameter; The overall performance reaches the optimum as fin height is 20.7 mm, fin density is 9.9, wave number is 11, wave angle is 4°; The multi-objective genetic algorithm combined with Kriging response surface eliminates the dependence on empirical relation. The results can be used to guide the optimum design of wavy fin tube.