The 5th～7th high order harmonics soft X-ray radiation with He in static gas target ranging from 40 nm to 160 nm driven by linearly-polarized 105 femtosecond Ti:sapphire laser at 795 nm are observed. The change of high-order harmonic intensity vs gas pressures is studied. The high-order harmonic intensity increases with gas pressures, but the optimal gas pressures have not been obtained considering the possible destruction to the detector under higher gas pressures.