The invention discloses a disposable bendable flexible template device and a construction method. The template device comprises an anchor rod, an anchor agent, a backing plate and a nut, a disposable bendable flexible hollow template is arranged on the inside of a surrounding rock, a rigid mesh sheet is arranged on the inside of the disposable bendable flexible template, the hollow template and the rigid mesh sheet are connected with the surrounding rock through the anchor rod, the anchor agent, the backing plate and the nut, as well as the inner cavity of the hollow template is filled with concrete. The construction method comprises that the flexible template is manufactured, the anchor rod is arranged, the flexible template and the rigid mesh sheet are arranged in a hanging way, the backing plate and the nut are arranged, and the concrete is poured. The invention has the advantages that the structure is simple, the construction is convenient, the supporting cost is low, the construction speed is quick, the template is arranged for once, and is not required to be disassembled for a permanent support, and the surrounding rock and the continuous overall concrete supporting body function commonly to bear the ground pressure. The cost can be saved by 150 Yuan to 250 Yuan per meter, and the supporting speed is improved by over 40 percent. The invention is suitable for mine working, railway, water conservancy, highway as well as defense engineering tunnel construction.