The invention relates to a recoverable flame-retardant reflective macromolecule roof waterproof roll and a preparation method thereof. The recoverable flame-retardant reflective macromolecule roof waterproof roll is prepared from the following raw materials in parts by weight: 40 to 55 parts of SEBS thermoplastic elastomer; 10 to 20 parts of thermoplastic polyurethane; 3 to 8 parts of titanium dioxide; 5 to 15 parts of extending oil; 15 to 30 parts of magnesium hydroxide flame retardant; 0.3 to 1.5 parts of oxidized polyethlene wax; 0.1 to 0.3 part of UV resistant agent; 0.1 to 0.5 part of light stabilizer; 0.1 to 0.3 part of antioxygen. In the formula provided by the invention, no plasticizer is added, and a co-extrusion processing is not used for multi-layer composition, so on the basis of ensuring good reflection, heat insulation, flame retarding, weather resistance and water-proof functions, recovery and reuse, and green and energy conservation are also realized.