The invention relates to plant-mixed cold-recycled emulsified asphalt. The plant-mixed cold-recycled emulsified asphalt contains ingredients, namely matrix asphalt, an emulsifier, hydrochloric acid, a stabilizer and water. A preparation method of the plant-mixed cold-recycled emulsified asphalt comprises the steps: (1) preparing soap spent lye: adding the emulsifier into water, adding the stabilizer, uniformly stirring, then, adding hydrochloric acid, adjusting the pH value of soap spent lye to 2-3, and heating the soap spent lye to the temperature of 60-80 DEG C; (2) preparing the emulsified asphalt: heating the matrix asphalt until the matrix asphalt is in a hot melt state, and adding the soap spent lye prepared in the step (1) and the matrix asphalt into emulsifying equipment, thereby obtaining the emulsified asphalt. According to the plant-mixed cold-recycled emulsified asphalt and the preparation method thereof, the plant-mixed cold-recycled emulsified asphalt has good storage stability and relatively good mixing time and construction workability, has very good adhesion to stone and is suitable for being subjected to plant-mixed cold-recycled construction.