The invention discloses a method for preparing anionic fluorine-containing polyacrylate soap-free emulsion. The method comprises the steps that acrylic monomers and fluorinated acrylate monomers are mixed to obtain mixed monomers, and an initiator and deionized water are mixed to obtain an initiator water solution; the initiator water solution, alkali, deionized water and an emulgator are weighed according to the mass of the mixed monomers, and the emulgator is fluorine-containing amphiphilic block copolymer poly(crylic acid-co-polyethylene glycol monomethyl ether methyl acrylate)-b-polyacrylic acid hexa-fluorin butyl ester; the mixed monomers and the initiator water solution are equally divided into three parts respectively; alkali, the deionized water, the emulgator, one part of mixed monomers and one part of initiator water solution are added into a four-mouth flask together; argon is introduced into the four-mouth flash, heating is carried out, the remaining mixed monomers and initiator water solution are added in the heating process, and the anionic fluorine-containing polyacrylate soap-free emulsion is obtained through cold water discharging. The anionic fluorine-containing polyacrylate soap-free emulsion with good emulsion particle stability can be prepared through the preparation method.