The invention discloses a light cement foam insulation plate which comprises the following raw materials in parts by weight: 70-80 parts of 52.5 general silicate cement, 40-50 parts of coal ash, 30-40 parts of silicon powder, 15-20 parts of river sand, 10-15 parts of fluorite slag, 5-10 parts of argil, 15-20 parts of plant straw powder, 18-25 parts of water glass, 20-30 parts of vermiculite, 8-12 parts of foaming agent, 1-2 parts of foam stabilizing agent, 1-2 parts of hydroxyethyl cellulose, 3-5 parts of modified tree ash, 1-2 parts of polycarboxylate high-performance water-reducing agent and 300-360 parts of water. The cement foam plate produced with the method has the advantages of excellent insulation and construction performances, good bonding effect, no empty drum cracking phenomenon, strong negative air pressure resistance, high strength, light weight, pressure resistance, good weather resistance, environmental protection, energy saving, non-toxicity, harmlessness and the like, and has very wide market space and development prospect in the field of building energy-saving applications in our country.