A gypsum plaster board is characterized in that the core board of the gypsum plaster board comprises following raw materials: gypsum, emulsion and nano particle modified glass fibers, and preferably,the raw materials of the gypsum plaster board comprise gypsum, emulsion, nano particle modified glass fibers, a foaming agent, a water reducing agent, modified starch and water. The preparation methodof the gypsum plaster board comprises the following steps: firstly, uniformly stirring gypsum, the emulsion, the nano particle modified glass fibers, the foaming agent, the water reducing agent, themodified starch and water to prepare gypsum slurry; secondly, pouring the slurry on surface protection paper, performing lap joint, firm adhesion and forming to prepare a wet board; finally, after thewet board is solidified, delivering the wet board to a drying machine, and drying the wet board. The provided gypsum plaster board is excellent in heat-conducting property, mechanical property and fire resistance. The longitudinal strength and the transverse strength of the gypsum plaster board with the thickness of 12 mm are improved by 53% and 75% respectively compared with those of a common gypsum plaster board, the heat conductivity coefficient is improved by 300% compared with that of the common gypsum plaster board, and the gypsum plaster board has wide application prospects in heat conduction building materials.