Abstract: Maleic anhydride(MA), styrene sodium sulfonate(SSS) and a hydrophobic monomer SH16 were used as materials, ammonium persulfate was used as initiator, then a novel inhibitor MSH was synthesized in this study. The structure of MSH was characterized by infrared spectrum and nuclear magnetic resonance, so as to evaluate the inhibition ability of MSH. The results showed that MA, SSS and hydrophobic monomer SH16 were effectively polymerized to the inhibitor MSH. When the Ba²⁺ concentration of the barium sulfate scale system was 370 mg/L, the scale inhibition efficiency was 91.3% of 50 mg/L MSH. Then the action mechanism of MSH was studied and the results showed that hydrophobic monomer SH16 improved the scale inhibition rate of MSH effectively. The results of the conductivity test showed that MSH could effectively extend the induction period of barium sulfate crystals and reduce the nucleation speed. The results of SEM showed that MSH could disrupt the normal sort of crystal lattice, making the crystal not to grow in accordance with the original order. In this way, the purpose of scale inhibition could be achieved.