Polyvinyl alcohol powder is suitable for building mortar additive, it can improve the water retention of mortar, improve mortar viscosity. In addition, it can reduce the friction of mortar, thereby enhancing the work efficiency and quality, prevent plastering layer cracking, falling off, increase the strength of adhesion and smoothness. PVA is widely used in powder building materials. Powder can quickly disperse in water, improve the initial adhesion property of building materials. Mainly used in thin layer binder, flexible binder, thermal insulation wall binder and add joint agent, etc.