To study the compression failure characteristics of foam concrete with different density， uniaxial compression tests of foamed concrete with density of 500-750 kg/m³ were carried out at different loading rates. Based on digital image correlation（DIC） and acoustic emission（AE） technology， the damage evolution of foam concrete was analyzed. The results show that with the increase of density， the yield stress， platform stress and energy absorption increase obviously. At the same time， the influence of loading rate is more obvious. The number of cracks decreases when the foam concrete is damaged， and the cracks change from vertical micro-cracks to shear cracks with inclined angle. The activity of AE signal before the peak increases， and the sudden increase of ring count is more concentrated at the damage. The failure behavior shows the tendency from ductile failure to brittle failure.