The phonon dynamics of the spin ladder calcium vanadium oxide is studied using Raman spectroscopy under high pressure up to 13.5 GPa. Twelve Raman modes, which are observed and assigned at low pressures, disappear at around 9 GPa. With further pressure increase, three broad modes appear at about 325, 750 and 810 cm(-1), indicating the transition of the layered structure into the disordered phase. No scattering activity is found above 13 GPa. The comparison between the vibrational properties of CaV2O5, alpha'-NaV2O5 and V2O5 indicates that anomalous 448 cm(-1) mode hardening in alpha'-NaV2O5 under pressure is also due to structural changes. The intercalation of Ca atoms results in a higher compressibility and stability of the CaV2O5 crystal structure in comparison with V2O5.