Method of preparing ether bond containing mixed long-carbon-chain triazine ultraviolet absorber

The invention relates to a method of preparing an ether bond containing mixed long-carbon-chain triazine ultraviolet absorber. The method includes: enabling benzenediol and alkaline compound to reactin a solvent to generate an intermediate-phenolate, removing generated water insoluble with the solvent in the process of reaction, and maintaining liquid of a reaction system to be in homogeneous phase; adding alkyl glycidyl ether for reaction to generate a target compound. By the method, in the first step, the water is constantly removed as alkali is reduced to enable the reaction system to be aliquid homogeneous-phase system, so that conversion of benzenediol is promoted, and conversion rate of benzenediol is increased; removal of the water is conducive to increasing reaction temperature and shortening reaction time. HPLC content of a crude product obtained by adopting the method can reach higher than 99.0%, so that aftertreatment operation is reduced, and convenience is brought to industrial production. 本发明涉及种