The InGaAsP material with an energy bandgap of 1.05 eV was grown on InP substrate by all-solid-state Molecular Beam Epitaxy （MBE） technique. The material had no mismatch dislocations between the substrate and the epitaxial layer， and also exhibited high interface quality and luminescence quality. Based on InGaAsP material， single-junction InGaAsP solar cells were grown on InP substrates， and GaInP/GaAs dual-junction solar cells were grown on GaAs substrates. These two separate cells were then bonded together using the wafer bonding technology to fabricate a GaInP/GaAs/InGaAsP triple-junction solar cell. Under the AM1.5G solar simulator， the conversion efficiency of the GaInP/GaAs/InGaAsP wafer-bonded solar cell was 30.6%， achieving an efficiency of 34% under concentration. The results indicate that MBE can produce high-quality InGaAsP material， and that room-temperature wafer bonding technology holds great potential for the fabrication of multi-junction solar cells.