For　pulse　Doppler　radar　to　detect　the　target　signal　which　is　spectrally　separated　from　clutter,　it　is　required　in　missile　hardware-in-the-loop　that　the　noise　resulted　by　clutter　reconstruction　architecture　should　be　60　dB　lower　than　the　main-lobe　clutter.　Because　of　the　restriction,　a　new　method　of　clutter　reconstruction　is　proposed,　which　includes　conversion　from　power　spectrum　to　vector　spectrum,　randomization　of　phase,　inverse　Fourier　transform,　and　then　windowing　and　overlapping　the　series　time　domain　sequence,　so　as　to　guarantee　the　continuous　expectation　value　and　variance　of　random　sequence.　Simulation　results　demonstrate　that　the　ratio　of　signal　to　noise　increases　from　30　dB　to　60　dB　by　applying　this　method.