Abstract: To study the cumulative damage law of surrounding rock caused by tunnel blasting excavation in watery karst area, the nondestructive testing field test based on ultrasonic detection and vibration monitoring is used to monitor the cumulative damage and vibration of tunnel surrounding rock under multiple cyclic blasting, and the evolution law of cumulative damage of tunnel surrounding rock under multiple blasting is analyzed. The experimental results show that the influence depth of the blasting on the tunnel rock is 1.2 meters. With the same loading amount, the disturbance of the blasting on the tunnel surrounding rock gradually weakens after the fifth blasting, within 23 meters from the blasting source. The test results can provide a reference for the safe excavation of tunnel blasting and the stability analysis of support structure through watery karst area.