Abstract: Catalytic gasification is a new type of coal gasification method, and the catalysts used in catalytic gasification are usually alkali metals. However, in catalytic gasification process, alkali metal catalysts react with Si and Al minerals in coal, directly affecting the catalytic activity of alkali metal in catalytic gasification. The deactivation behaviors of alkali metals and Na-Al reaction and transformation during catalytic gasification with Na_2CO_3 addition was studied. Kaolinite and boehmite were used as model compounds to study the Na-Al reaction and conversion process, and the catalytic effects of Na-Al conversion products were compared. The study shows that Na_2CO_3 has good catalytic effect. During catalytic gasification, Na_2CO_3 reacts with Si and Al minerals in coal to form nepheline and sodium aluminosilicate, resulting in catalyst deactivation. Kaolinite reacts with Na_2CO_3 at 700 ℃ to form sodium aluminosilicates, and boehmite reacts with Na_2CO_3 at 860 ℃ to form NaAlO_2, which is unstable at higher temperature and is converted into sodium aluminosilicates. Compared with Na_2CO_3, the catalytic effect of sodium aluminosilicates and NaAlO_2 is poor, resulting in the deactivation of Na_2CO_3, and the catalytic effect of NaAlO_2 is better than that of sodium aluminosilicates.