The invention relates to improved Venetian plaster and the application thereof. The improved Venetian plaster comprises the following components in parts by weight: 20-50 parts of sulphoaluminate cement, 20-35 parts of Portland cement, 0.2-1 part of water reducer, 1.5-4 parts of silica fume, 1-4 parts of slag powder, 1-3 parts of coal ash, 0.1-1 part of thickener, 1-4 parts of redispersible powder, 20-35 parts of silica sand powder, 0-5 parts of organic color paste and 0-5 parts of inorganic color powder, wherein the ratios of the slag powder and coal ash to the total weight are both greater than or equal to 2%. The improved Venetian plaster disclosed by the invention has good water resistance, oil resistance and weather fastness, is safe, environment-friendly, durable, elegant and luxury, has unique artistic decoration effect, can replace traditional coating and tiles, and can be applied to inner wall decoration of buildings.