The invention discloses a novel environmentally-friendly decorative plate material, which includes the following raw materials: waste and old plastic, alumina silicate fibre, a smoke suppressor, chitosan, an antiradiation agent, calcium carbonate, wollastonite powder, diatomite, a fire retardant, a mildew inhibitor, a coalescing agent and environmental glue. The decorative plate material of the invention has low material cost, is easy to prepare, is harmless to human body and is convenient for people to use for a long time. Since diatomite which has a natural microporous structure is added in the raw materials, respiratory humidification can be realized, and diatomite can also adsorb toxic and harmful substances in the air to improve the indoor environment. Since alumina silicate fibre has characteristics of high temperature resistance, good heat stability, low thermal conductivity, elasticity, sound insulation, electric insulation, good chemical stability, etc., the material has high temperature resistance and other characteristics and is endowed with more advantages. By using lots of waste and old plastic as the raw material, the waste and old plastic can be reused, and utilization rate of the waste and old plastic is increased.