To reveal the demulsification behavior and mechanism of emulsified asphalt in CA mortar, the particle size distribution fluctuation and coagulation of anionic emulsified asphalt in the salt solution were investigated. The demulsification degree was controlled by adding CaCl2 and chelating agent, and the demulsification behavior of anion emulsified asphalt on rheological properties of CA paste were investigated. The results indicate that for the anionic emulsified asphalt clustering into demulsification in the salt solution the greater the cation valence state, the higher the cation concentration; the longer the mixing time, the more intense the anionic emulsified asphalt coagulation was. The cation released with cement hydration prompted the coagulation demulsification of anionic emulsified asphalt, which increased the internal friction of CA paste in viscous deformation, resulting in the loss the rheological property of CA paste.