Thickening intensive water retention additive for dry mortar is a kind of non-air-entraining and non-lime type powder composite agent, which consists of inorganic mineral materials and organic polymer. The agent is non-toxic, no radioactive, no corrosive, safe and environmental. The dry mortar mixed with the agent could totally take place of lime paste used in painting mortar, masonry mortar, and other constructional mortar. Compared to similar product in current market, the ratio of our agent to cement is small, cost is lower, water retention is better, workability is better, mortar strength is higher.