The Yellow River sediment was activated by NaHSO4. The influence of NaHSO4 on the stabilizability, strength, plasticity and its mechanism were analyzed by X ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and magic angle spinning nuclear magnetic resonance(MAS NMR). Experimental results show that the stabilizability of sediment significantly improve in the presence of NaHSO4. Strength, plasticity and softening coefficient of sediment increase with NaHSO4 mass fraction. When mass fraction of NaHSO4 is 6%, pozzolanic activity index(PAI) reaches 064 and softening coefficient is 036. FTIR, XRD and MAS NMR spectrum results indicate that activation of NaHSO4 induces the deflection Si—O—Al bond angle of feldspar and the decrease of polymerization of Si—O tetrahedron network. Engineering properties of Yellow River sediment is improved under the activation of NaHSO4.