The invention discloses a petroleum series solvent soluble fluorine-containing composition and a preparation method thereof. The composition comprises the following components in parts by mass: 0.1-15parts of a fluorine-containing copolymer with reaction activity groups, 75-99.9 parts of a petroleum series solvent and 0-10 parts of a non-double bond alkoxy silane compound. The preparation methodof the composition comprises the following steps: firstly, performing a polymerization reaction in a solvent of which the polarity is not less than that of aromatic hydrocarbon; secondly, heating at avacuum state to remove the solvent of which the polarity is not less than that of aromatic hydrocarbon; when the content of the copolymer is greater than 65%, introducing an inert gas; and after thesolvent of which the polarity is not less than that of aromatic hydrocarbon is completely removed, adding a proper amount of the petroleum series solvent into the system. By adopting the preparation method, active groups can be effectively prevented from cross-linking in the process that the solvent of which the polarity is not less than that of aromatic hydrocarbon is removed, a small amount of the solvent of which the polarity is not less than that of aromatic hydrocarbon is left in the obtained petroleum series solvent soluble fluorine-containing composition, in addition, the petroleum series solvent soluble fluorine-containing composition is uniform and transparent, and the properties of the composition are approximate to properties of a fluorine-containing composition in a solvent ofwhich the polarity is not less than that of aromatic hydrocarbon.