The present invention relates to long linear alkyl alkyl ether and a polymerization method thereof. The long linear alkyl alkyl ether is prepared by reacting long linear alkanol and alkyl allylhalide with a molar ratio of 1:1-1.5 under the action of strong base. The polymerization method is simple and reasonable in process, cheap and easily available in used raw materials, high in reaction yield, and low in production cost, and has no three waste emission and has great social economic benefits. The comb-shaped polymer obtained by long linear alkyl alkyl ether polymerization can be used for synthetizing oil-absorbing resin.