Abstract: The invention a fluorinated dendrimer and a preparation method thereof. The preparation method of the fluorinated dendrimer include the following steps: S1, obtaining an intermediate product by addition reaction of 4-fluoroaniline and methyl acrylate at room temperature; S2, stirring the intermediate product with 1,3-diamino-2-propanol and methyl acrylate at room temperature to obtain a mixture; S3, performing a stage heating reaction of the mixture under a reduced pressure condition to obtain the fluorinated dendrimer. The fluorinated dendrimer can solve the problems of high demulsification temperature, large dosage, and low demulsification efficiency of existing demulsifiers.