The invention provides weather-resistant polymer modified asphalt cement waterproof paint. The paint is composed of a component A and a component B; when the paint is used, a liquid material is mixedwith a powder material according to a ratio of 1 to (0.8-1.2). The component A is prepared from the following raw materials in parts by weight: 30-60 parts of asphalt, 3-15 parts of SBR, 1-6 parts ofSBS, 8-12 parts of sodium silicate, 5-10 parts of modified silicon dioxide ultrafine powder, 1-6 parts of an emulsifier I, 1-6 parts of an emulsifier II, 0.2-2 parts of an ultraviolet stabilizer, 0.5-2 parts of a stabilizer, 1-5 parts of a dispersant, 0.1-1 part of a defoaming agent, 20-60 parts of water and 0.5-2 parts of a corrosion inhibitor. The component B is prepared from the following raw materials in parts by weight: 25-35 parts of cement, 55-65 parts of calcite powder, 95-105 parts of talcum powder and 0.5-1.5 parts of a water reducer. Polymer modified asphalt, sodium silicate and theultraviolet stabilizer are added into the paint; through adjustment and collocation of composition and ratio of the components, the polymer cement waterproof paint with excellent water resistance, flexibility, compactness and weather resistance can be prepared.