Five times. The light on the lighthouse flashed five times, which took 26 seconds. According to mathematical operation, it flashes once every 5.2 seconds on average, so it flashes at most 5 times every 30 seconds. The lighthouse is a tall tower building. Lighting equipment should be installed in a prominent position at the top of the tower, and pay attention to its specific architectural shape, which is convenient for ships to distinguish and become one of the highest points of the port.