To explore the response of a double-row steel sheet pile cofferdam under the condition of different wave modes, the effects of near breaking wave and standing wave on steel sheet piles was compared through flume test using optical fiber testing technology, and the mechanism of wave load caused by standing wave and near breaking wave was analyzed. It is found that the main unfavorable effect of standing waves on the double-row steel sheet pile cofferdam is the scouring of the seaside steel sheet piles caused by the reflected waves. The main unfavorable effect of the breaking wave on the double-row steel sheet pile cofferdam is the huge crushing energy and rapid impact during wave breaking. The deformation of the steel sheet pile may cause accidents such as leakage of the joint and soil erosion of the infilled sands.