The invention discloses a high-weather resistance thermoplastic polyolefin waterproof roll hot-melt pressure-sensitive adhesive and a preparation method thereof and belongs to the technical field of pressure-sensitive adhesives. The hot-melt pressure-sensitive adhesive is prepared from the following raw materials in parts by weight: 20 to 40 parts of SIS elastomer, 3 to 10 parts of visco-elastic modifying material, 2 to 8 parts of cross-linking agent, 0.5 to 2 parts of antioxidant, 0.05 to 0.5 part of initiator, 15 to 30 parts of softener and 35 to 60 parts of tackifying resin. The high-weather resistance thermoplastic polyolefin waterproof roll hot-melt pressure-sensitive adhesive disclosed by the invention can be used for manufacturing a self-adhesion thermoplastic polyolefin waterproof roll. As organic solvents are not used in the raw materials for preparation and a preparation process, the pressure-sensitive adhesive belongs to a solvent-free pressure-sensitive adhesive, drying time is short, environment is not polluted in a construction process, and health of constructors is not harmed. The obtained pressure-sensitive adhesive is good in initial adhesion, excellent in persistent adhesion, high in peel strength, good in weather resistance, high in softening point and suitable for various severe environments, such as low temperature.