The invention discloses an asphalt cement mortar, which is a compound synthesized by dry materials, emulsified asphalt, water-reducing agent, defoaming agent and water pro rata. Each component in the mixture is calculated in portions by weight: 70-80 portions of the dry materials, 10-20 portions of the emulsified asphalt, 0.1-0.4 portion of the water-reducing agent, 0.005-0.01 portion of the defoaming agent and 8-15 portions of the water. The dry materials consist of cement, aggregate and expansion agent. Each component in the dry materials is calculated in portions by weight: 35-42 portions of the cement, 58-65 portions of the aggregate and 0.0015-0.0025 portion of the expansion agent. The component proportion of the asphalt cement mortar of the invention is proved by a great number of experiments and can lead each component to be fully used and generate synergistic effect. The invention has appropriate intensity and elasticity, good weather resistance and construction ability and can completely meet the need of plate-typed unballasted track construction in railways or in cities. Furthermore, the raw materials of the components of the invention are all produced in domestic, thus greatly saving cost.