The invention provides a method for preparing a comb-type polyether polyurethane macromolecular ionic liquid material by hydroxy-terminated polyepichlorohydrin (PECH), mainly comprising four steps, wherein, the main chain and the short side chain of the obtained macromolecules both take polyether structures. A polyether chain is a flexible chain, with low glass transition temperature; the ether bonds on the main chain and the side chain can complex with some metal ions; and the side chain also comprises ionic liquid groups, thereby having higher conductivity and good mechanical property and wide range of applications. The prepared comb-type polyether polyurethane macromolecular ionic liquid material can realize adjustable conductivity and electrochemical windows of the material by compounding with small molecular ionic liquid or inorganic salt. The comb-type polyether polyurethane macromolecular ionic liquid material has the characteristics of flexible, transparent and easy molding.