NOVELTY - A trimethyladamantylammonium hydroxide, tetraethyl ammonium hydroxide, aluminum source, silicon source and water are mixed, and aged. The obtained sol is added to stainless steel reactor, and reacted. The obtained reaction solution is centrifuged and washed. A porous support is polished, ultrasonically cleaned and dried. The zeolite crystals are coated on the outer wall of the support. The coated support is placed in the sol, and reacted. The obtained product is cleaned, dried and calcined, to obtain SSZ-13 zeolite membrane.    USE - Preparation of high-silica CHA-type SSZ-13 zeolite membrane used for separating inorganic gas e.g. hydrogen, carbon dioxide and nitrogen gas from low-carbon hydrocarbon, and separating 1-3C low-carbon hydrocarbon e.g. ethylene/ethane.    ADVANTAGE - The method enables preparation of high-silica CHA-type SSZ-13 zeolite membrane with high chemical stability and water vapor resistance.    DETAILED DESCRIPTION - A trimethyladamantylammonium hydroxide, tetraethyl ammonium hydroxide, aluminum source, silicon source and water are mixed, and aged for 1-12 hours with stirring, to obtain sol (A). The sol is added to a stainless steel reactor, and hydrothermally reacted at 120-250 degrees C for 6-84 hours. The obtained reaction solution is centrifuged and washed, to obtain SSZ-13 zeolite crystals. A porous support is polished, ultrasonically cleaned and dried. The zeolite crystals are coated on the outer wall of the support. The trimethyladamantylammonium hydroxide, tetraethyl ammonium hydroxide, aluminum source, silicon source and water are mixed, and aged for 12-72 hours, to obtain sol (B). The sol (B) is added to the stainless steel reactor, coated support is place in the sol, and hydrothermally reacted at 120-250 degrees C for 8-96 hours. The obtained product is cleaned, dried and calcined, to obtain SSZ-13 zeolite membrane. The molar ratio of silica and aluminum oxide in the sol (A) is 10-300. The molar ratio of trimethyladamantylammonium hydroxide and silica in the sol (A) is 0.1-1. The molar ratio of tetraethyl ammonium hydroxide and silica in the sol (A) is 0.1-1. The molar ratio of water and silica in the sol (A) is 20-100. The molar ratio of silica and aluminum oxide in the sol (B) is 10-700. The molar ratio of trimethyladamantylammonium hydroxide and silica in the sol (B) is 0.1-1. The molar ratio of tetraethyl ammonium hydroxide and silica in the sol (B) is 0.1-1. The molar ratio of water and silica in the sol (B) is 20-200.