The high viscosity of heavy oil is a vital parameter that hinders the heavy oil recovery efficiency. Viscosifying aqueous viscosity and reducing oil phase viscosity are the guiding principles under our current study to improve the offshore heavy-oil recovery using the cold production method. To achieve this goal, a novel amphiphilic macromolecule (HOA, already reported in our previous paper) has been synthesized by grafting three functional moieties onto the acrylamide backbone, which provides HOA both emulsifying and asphaltene dispersion capacities. To manifest the enhanced oil recovery (EOR) mechanisms of HOA, all experiments were carried out with hydrolyzed polyacrylamide (HPAM) being a baseline. Consequently, when comparing the results of HPAM and HOA, it is found that the functional groups on HOA bring distinct properties to HOA, including both increasing displacing phase viscosity and reducing displaced phase viscosity. In detail, the bulk phase viscosity-concentration relationship proves that HOA generates significantly higher viscosity than HPAM at the same concentration, giving rise to a better mobility control performance. Furthermore, HPAM does not show any surface-active ability. In contrast, HOA lowers the oil-brine interfacial tension (IFT) from 37.8 to 1.4 mN/m and forms oil-in-water emulsion at a relatively low water content of 20%. As another means to reduce the viscosity by HOA, the asphaltene dispersion capacity reaches similar to 32% by conducting ultraviolet (UV)-absorbance experiments. Furthermore, the underlying dispersion mechanism is confirmed by X-ray diffraction (XRD) results, which demonstrate that HOA has loosened asphaltene cluster structure, thus reducing heavy oil viscosity. Overall, our laboratory results have paved the way for the future field application of HOA on offshore heavy oil oilfields.