The invention discloses an ecological plate made of straws and forestal residues and a method for preparing the ecological plate, which relate to the technical field of building decoration materials. The ecological plate consists of components, by weight, including from 45 to 48 parts of fine straw fibers, from 45 to 48 parts of fine forestal residue fibers, from 2 to 4 parts of adhesive, from 1 to 3 parts of flame retardant and from 1 to 3 parts of water repellent, and the ecological plate is processed by the aid of working procedures including chopping and crushing, preparing the fibers, beaching, adding the additives (the flame retardant, the water repellent and the adhesive), mixing and stirring, drying, briquetting and forming, adhering a decorative plate, forming a commercial plate and the like. The ecological plate has various advantages of low production cost, ecological property, environmental protection, high density and strength, wide material source, waterproofing, fireproofing and the like, is a medium and high-density composite fiber plate, can be widely applied to non-load bearing wall materials in frame structure and steel structure engineering, wall partitions for indoor decoration, wall partitions of factories, shopping malls and enclosing walls of plant areas, walls of trailer coaches and farm houses and the like, and is an environment-friendly product which is widely popularized according to wall modification policy of the country.