Abstract: An analysis about optimizing the column arrangement of horizontal tube bundles in falling film evaporators was carried out with numerical simulation by distributed parameters in large compression refrigeration systems. In this simulation, the model considered the evaporation heat transfer performance on horizontal copper tube bundles with liquid refrigerant HFC134a. The impacts of some factors, such as the column number of falling film tube bundle and the number of flooded tube row on the evaporator performance were analyzed. In addition, a parameter of uniformity factor of mass flow field was set up to evaluate the heat transfer performance of evaporators. The results indicate that the less the column number of the falling film tube bundle is arranged, the less the dry patches on falling film tube surfaces, the greater the uniformity factor of mass flow field and the better the heat transfer performance of evaporators under the same flooded tube rows.