Abstract: In high-frequency sky wave radar system, the long-range spread clutter folded into the radar receiver will submerge the low-Doppler region and seriously affect the detection performance of the low-velocity target. In order to achieve the target detection correctly, it is necessary to suppress the rangefolded clutter. In this paper, an inter-pulse phase coded waveform is designed to suppress the range-folded spread clutter,and the waveform parameters can be updated in real time. This waveform can narrow down the rangefolded spread clutter while moving it to the specified spectrum area. The parameter design method is given and the viability of the waveform is analyzed. Simulation results show that this waveform can effectively suppress rangefolded spread clutter.