The invention relates to a self-flame-resisting type acrylic emulsion. The self-flame-resisting type acrylic emulsion is characterized in that according to a self-flame-resisting type modified styrene-acrylic emulsion, reaction type halogen-containing flame-resisting type vinyl monomer and acrylic esters monomer can be in emulsion copolymerization, a flame-resisting group is fixed on a resin molecular structure in a chemical bond mode and cannot resolve or drop, synthesized acrylic emulsion has self-flame-resisting property, and when coating is prepared, another flame retardant is not required to be added, and long-lasting flame-resisting property can be realized. The invention further provides a preparation method of the self-flame-resisting type acrylic emulsion. The prepared self-flame-resisting type acrylic emulsion has good adhesion, water tolerance and durability, and a prepared film has water tolerance, alkali resistance, scrubbing resistance and long-lasting self-flame-resisting property, and the self-flame-resisting type acrylic emulsion is widely used for flame-resisting coating of indoor and outdoor woodware, steel structures and buildings, not only has a decorating function, but also has a protecting function.