Abstract: To improve the air-side heat transfer efficiency and reduce the resistance of fin-and-tube evaporator, this paper combines the method for modular modeling calculation and the algorithm for linear regression with multiple variables to construct the mapping relationship models of flow rate, pressure drop and the structure parameters of the evaporator. And based on the mapping relationship model, the multi-objective optimization is aimed at achieving maximum the Colburn factor and minimum friction factor by the NSGA-Ⅱ algorithm with regards to design variables, the row spacing and tube spacing of evaporators. According to this, the set of multi-objective optimization is analyzed and verified by the following four aspects: maximizing the air-side heat transfer efficiency, minimizing the air-side friction, significantly reducing the friction based on a small loss of heat transfer efficiency, and compromising the heat transfer efficiency and friction. The error between the final optimization results and the simulation results is less than 5.6%, and compared to the initial structure parameters of the evaporator, the heat transfer efficiency and resistance characteristics have been improved to varying degrees.