Qomroud water conveyance tunnel (lot 1&2) with the length of 16 kilometers is considered as one of the greatest development and national projects in Iran. Since about 2 kilometers of tunnel pass through alluvium and the rest of the tunnel pass through various types of geological units, and due to the complexity of geological condition and variety of effective criteria, suitable selection of excavation machine is crucial. In this respect, application of a suitable method which can select the best, according to the consideration of these entire criteria would be so important. One of the best decision making methods is Analytic Hierarchy Process (AHP) which has a strong theoretical basis. Using this method, this paper selects the most suitable excavation machine for Qomroud water conveyance tunnel. The results show that the EPB TBM Single Shield is the best alternative.