The CiADS project is composed of the proton driver linac,target and nuclear reactor,this ADS demonstration facility will be designed and built with 500 MeV in energy and 5 mA in beam current.The proton accelerator should be operating in continuous wave(CW)mode,and it will deliver 5 mA CW beam to the target.The proton linac contains two main sections,one is the normal conducting section and the other is the superconducting section.The room temperature four-vane RFQ in normal conducting section will accelerate the proton beam to 2.1 MeV,and the downstream SC section as the main accelerating component can accelerate the proton beam from 2.1 to 500 MeV.