A　periodic　structure　of　bonded　GaAs　wafers　can　be　used　for　high　power　quasi-phase-　matched　second-harmonic　generation　of　a　CO2　laser.　The　fabrication　of　the　QPM　GaAs　based　on　wafer　bonding　technology　and　interfacial　properties　of　this　crystal　were　studied.　Hydrogen　ion　beam　was　used　to　remove　the　oxide　layer　on　the　GaAs　surface　to　improve　its　optical　properties.　Pre-bonding　process　in　the　ultra-high　vacuum　reduced　the　microspores　density　of　the　bonding　interface.　Heat　treatment　increased　the　bonding　force.　Thus　a　reliable　bond　of　the　two-layer　GaAs　was　realized.　The　two-layer　GaAs　combined　into　a　single　crystal　structure　without　amorphous　layer　formed　by　oxide.　By　this　bonding　process　a　periodic　polarization　reversed　GaAs　crystal　with　large　aperture,　low　loss　was　obtained,　therefore　providing　a　way　for　realizing　high　power　frequency　doubling　of　CO2　laser　using　quasi-phase-matching　technology.