The present invention relates to a method of preparing a decadodecasil 3R (DDR) type zeolite membrane and a membrane prepared thereby, and more particularly, to a method of preparing a hydrophobic decadodecasil 3R (DDR) type zeolite membrane having a continuous out-of-plane orientation by adding a substrate on which a seed layer is formed to a silica source synthetic precursor containing a methyltropinium salt and performing a hydrothermal synthesis, and a method of capturing and removing carbon dioxide using a membrane prepared thereby.