Based on the technique of PIV (particle image velocimetry),We calculated the light intensity of the bubble interface and discovered that the intensities of lighr reflected or refracted twice succeedingly abide by the rules of geometric series, and the light will disappear after reflecting or refracting 4 times by the bubbles. When the angle of incidence of 35° is avoided , the intensity of second refraction out of a bubble is independent of the incident beam width, similar to the case of a narrow light ray falling on the bubble interface. The integral formulas for the intensities of reflection or refraction are given for the planar light beam falling on the bubble interface. The numerical solution of the integral is in agreement with the experiment value.