The multiferroic BiFeO3 crystals were studied under high pressures up to 70 GPa created in diamond anvil cells. Electronic, magnetic and structural transformations were found in the region 40-55 GPa. Electronic transition with high-to-low spin crossover of Fe3+ ion, suppression of magnetism and metallization were carefully investigated and documented. All transitions are completely reversible. The proposed theoretical consideration explains some details of the high-pressure magnetic, optical and electronic properties.