The present invention relates to a method of constructing a functional roadside waterproofing structure, which is capable of preventing the damage of roadside trees by securing permeability and strengthening the strength of the roadside walls, To solve the problem. The functional roadside water protection structure according to the present invention comprises: a ground reinforcement layer (10) laid on a ground on which a roadside tree (1) is planted； Wherein the ground reinforcement layer comprises a blast furnace slag powder, a fluidized bed boiler slurry, a paper ash, an alpha-type hemihydrate gypsum powder, 5 to 10 parts by weight of a solid phase solidifying agent composed of at least two of calcium sulfate-aluminate (CSA) powder, calcium lime and calcium hydroxide, and 5 to 10 parts by weight of a reaction liquid and a ground reinforcement material Wherein the polymeric roadside protection layer comprises 10 to 20 parts by weight of a non-yellowing polymer composite comprising an isocyanate-based polymer, a polypropylene-based polymer and an additive material mixed with 100 parts by weight of the aggregate And a polymer protective material. A method of constructing a functional roadside protection structure according to the present invention comprises: a first step of planarizing a ground in which a roadside tree is planted； (100 parts by weight of the recycled aggregate) on the flat ground through the first step, the blast furnace slag powder, the fluidized bed boiler furnace, the paper ash, the alpha type hemihydrate gypsum powder, the calcium sulfo-aluminate (CSA) powder, 5 to 10 parts by weight of a solid solidifying agent composed of at least two of calcium hydroxide and 5 to 10 parts by weight of a reaction liquid and a natural soil of the ground where the aqueduct is planted, A second step of constructing； Polymer protecting material composed of 10 to 20 parts by weight of a non-yellowing polymer composite comprising an isocyanate-based polymer and a pol
