The invention belongs to the field of thermosetting polymer materials, and in particular relates to a thermosetting polymer compound, a poly-half-amide supermolecular film and a preparation method thereof. The preparation method comprises the following steps: (1), preparing a paraformaldehyde and nonprotic / water mixed solvent into a suspension, depolymerising, and cooling to room temperature to obtain a formaldehyde reaction solution; (2), dissolving aromatic diamine and / or aromatic triamine in a nonprotic solvent to obtain an aromatic amine reaction solution; and (3), uniformly mixing formaldehyde with the aromatic amine reaction solution, pre-polymerizing, further spreading a film on a horizontal glass plate, and drying and solidifying so as to obtain the film. The film is adjustable in thickness, colourless and transparent; the light transmittance is greater than 90%; the Young modulus, the tensile strength, the breakage elongation and the tensile failure energy of the film can respectively achieve 3-6 GPa, 70-100 MPa, 2-5% and 0.7-2.5 MJ / m<3>; aromatic amine serving as the main raw material in the film can be recycled; and the recovery rate can be above 95%.