As a result of recent climate warming,GLOFs become more frequently. More and more researchers focus on the mechanism of GLOFs,and find most of GLOFs are initiated by waves from ice avalanches that collapse into lakes. Under laboratory conditions,this paper studies the development and characteristics of dam failure caused by waves and focuses upon the effects of the different scales of waves on dam failure. Conclusions as followed: 1. Waves overtopping and erosion result in dam failure,and the breach gradually forms in the wake of the initial wave and the following waves. With the interaction of incision,lateral erosion and retrogressive erosion,the erosion rate increases and peak discharge emerges. 2. The lager the waves,the more the initial wave erodes dam crest,the higher the dam erosion rate,the thinner the instant profiles of dam every 1 second. Due to the higher rate of lateral erosion on the condition of static water level,the breach is wider than the dynamic one. 3. Under the condition of static water level,the first wave overtopping forms the initial discharge Q_0,and the larger the waves,the larger the initial discharge Q_0. Peak discharge Q_m appears at the beginning of the dam failure,Q_m forms earlier when the waves are larger.