Abstract: In order to accurately characterize the particle size and distribution characteristics of emulsified asphalt, the correlation between particle size and early strength was studied. Based on the test results of the laser particle size analyzer, the effects of shear time, soap pH, stabilizer content, emulsifier, and emulsification equipment on the particle size were analyzed. Based on the results of the cohesive force test, the correlation between the particle size of emulsified asphalt and the early stage of the mixture were evaluated. The results showed that: the average particle size D50 and the thick end particle size D90 had basically the same characterization results for the particle size evolution, and the single peak distribution was better than the double peak and no peaks. With the extension of the shear time, the particle size first decreased and then increased. When the soap pH value was less than 2.0, the particle size was less affected. When the stabilizer content was greater than 0.3%, it would change the electric potential characteristics of the emulsified asphalt micelle ion double layer. The emulsifying ability of the emulsifier had a greater impact on the particle size than the amount of emulsifier. The degree of influence of the emulsification equipment depended on the emulsifying ability of the emulsifier. Compared with the storage stability, the particle size had a better correlation with the early strength of the mixture, and the correlation coefficient was 0.96. This was because the smaller the particle size, the larger the specific surface area of the asphalt particles in the emulsion system. After demulsification, the asphalt was more likely to coalesce under the charge of the emulsifier to form strength.