Stress wave propagation and attenuation laws of underground openings reinforced by dense bolts at anchor top and long-dense bolts are studied by anti-explosion model tests under repeated top explosions. After each explosion, with the increase of scaled stance, peak pressure stresses on vault gradually decrease in the form of a power function, and the corresponding power functions to fit the curves are obtained, of which the indexes of fitting stress wave attenuation are smaller than those of undisturbed rock. Under the action of explosion stress waves, the rock near the anchorage zone is compacted firstly, and then damaged continuously. Under the same conditions of explosions, with the increase of scaled stance, the difference of pressure stresses with two underground openings is reduced gradually at the same scaled stance and peak pressure stress on vault of the underground opening reinforced by dense bolts at anchor top is greater than that of the underground opening reinforced by long-dense bolts firstly at the same scaled stance, and then smaller. Under the same conditions of explosions, the stress wave attenuation law and peak pressure stress of the nearest measuring points from two underground openings are similar.