In order to study the bubble pulsation characteristics of low energy detonating cord, an underwater explosion experiment was carried out by high-speed photography technology.The experimental results show that the bubble pulse shape in the shooting section remains a clindricclity at the first bubbles pulsing tirme, and iregular cylinder from the second bubbles pulsing tirme. The outside edge of bubbles is blurry because of the efect from shell fragments.The first bubble pulsation period is 21.5 ms and the second is 15.5 ms.The maximum diameter of bubble is 11.2 cm in the first bubble pulsation period.In addition, the bubble growth time is 15 ms while the contraction time is 6.5 ms in the first bubble pulsation period.The bubble growth time is longer than the contraction time.