Disclosed is a light-blocking tarpaulin sheet, comprising a piece of light shielding cloth (1) and sucking and fastening members (2), wherein the light shielding cloth (1) is provided with a light reflection layer (3) on one surface thereof; the light shielding cloth (1) is of a square structure, and through holes (4) are provided on the periphery of the light shielding cloth (1); each of the sucking and fastening members (2) comprises a handle (5) and a suction cup (6) joined integrally; the handle (5) is perpendicular to the suction cup (6), a groove (7) is provided in the handle (5), and the handle (5) is inserted into the respective through hole (4); the through hole (4) is arranged at the groove (7), and the suction cup (6) and the light reflection layer (3) are provided in the same direction. The suction cup can be directly adhered onto glass and is convenient and quick to use, there is no trace after removal, and it can be used multiple times, can be assembled or folded, has a wide application range and low costs, and improves efficiency.