In order to develop a new type of slick water drag reducer, this paper uses terpolymer of acrylamide (AM), hydrophobic monomer dodecyl dimethylallyl ammonium chloride (C12DMAAC), and sodium acrylate (NaAA) as raw materials. The long-chain end-group hydrophobic associative polymer HPAM-L was synthesized by the self-made long-chain hydrophobic initiator AIBL. The performance was characterized, and the friction resistance of HPAM-L solution at different concentrations was measured by a flow loop friction tester. The results show that the viscosity-average molecular weight of HPAM-L is about 7.43 × 106 g/mol, the critical association concentration is about 1～1.5 g/L, and it has good temperature resistance and shear stability. The aqueous solution of HPAM-L has a wide range of Linear viscoelastic region, and the higher the concentration, the more obvious the elastic characteristics. When the solution concentration is 0.075%, 0.086%, 0.1% and 0.15%, the maximum drag reduction rate can reach 71.6%, 73.1%, 73.3% and 74.1%, respectively, and the drag reduction performance is good.