The invention discloses a method for preparing nano-scale sodalite molecular sieve formed matter. The pure nano-scale sodalite molecular sieve formed matter can be prepared under the condition that no organic additive or structure-directing agent exists. The method includes the steps that 1, a solid-phase silicon source and a solid-phase aluminum source are mixed evenly, a first alkaline aqueous solution is added, the mixture is stirred evenly and formed, and formed matter is obtained; 2, the formed matter is dried and then roasted; 3, the roasted formed matter is put into a second alkaline aqueous solution, and after crystallization, the nano-scale sodalite molecular sieve formed matter is obtained.