The invention discloses a synthesis method of 4,4-bisphenol F. The synthesis method of 4,4-bisphenol F is characterized by comprising the following steps: pouring 150 parts (by weight) of phenol, 60-90 parts of 85% phosphoric acid and 60-90 parts of solvent in a reactor, stirring for 1-3 hours at 45-65 DEG C, dripping 22-33 parts of 37% formaldehyde, keeping the reaction temperature at 45-65 DEG C, controlling the dripping time to be 2-8 hours, then reacting for 0.5-2 hours at 45-75 DEG C, standing for layering, removing lower-layer colourless and transparent liquid, and then filtering upper-layer white and turbid liquid; washing a filter cake by the solvent, then washing the filter cake to be neutral by distilled water, drying, then mixing and dissolving with 40-78 parts of absolute methanol, then adding the obtained methanol solution in 66-128 parts of distilled water and mixing, separating out solid substances, filtering and drying to prepare 4,4-bisphenol F. According to the synthesis method disclosed by the invention, 4,4-bisphenol F is prepared by a pure phosphoric acid catalysis method, and the synthesis method is suitable for industrial production and high in practicability.