The invention relates to a propylene glycol ether preparation method, mainly solving the shortcomings that catalyst of the prior art has low stability and imperfect products yield and isomers proportion. The invention adopts epoxy propane and higher fatty alcohol as materials, adopts niobium oxide as a main activated component, and chooses at least one of elements or oxides of Ge, Sn, Pb, P or S as auxiliary agent to form the catalyst, to prepare propylene glycol ether under the temperature of 100 to 300 DEG C, reaction pressure 1.0 to 3.0MPa, lower fatty alcohol/ epoxy propane ratio 1-10: 1,liquid space velocity 1.0 to 4.0 hour<-1>. The technical proposal can well solve the problem, and has epoxy propane conversion rate higher than 98 percent, propylene glycol ether selectivity higher than 95 percent, and isomers proportions higher than 95: 5. The method of the invention can achieve comparatively high product yield and isomers proportion, and has the advantages of small energy consumption, low production cost, environmental protection and free of device corrosion, and can be used for industrial production of the propylene glycol ether.