The invention relates to a method for preparing an architectural decoration used nucleated glass-ceramic composite board. The method is a preparation process of single firing of the nucleated glass-ceramic composite board, which is characterized in that the method comprises the steps of: (1) preparing ceramic powder; (2) preparing dry ceramic powder; (3) preparing master glass granule; (4) pretreating the master glass granule: the master glass granule and sodium cellulose glycolate solution are mixed according to the mass ratio of 1:0.02 to 1:0.1 before the dry ceramic powder and the master glass granule are mixed according to the mass ratio 1:4 to 1:8; (5) distribution and compaction: the master glass granule covered with ceramic is uniformly distributed at the bottom of the die cavity of a brick press at 1.2 to 4kg per m<2> before the ceramic powder is filled in the die cavity of the brick press, thus extruding the green compact of the composite board; (6) drying and burning; (7) polishing and treating. The method has the advantages of low consumption of productive energy, few pore defects of the products, high content of nucleated glass phase in the surface of the composite board, and good ornamental effect.