The effects of alcohol compound (A₁) and carboxylic compound (A₂) as crystal modifiers on the crystal morphology of ε-HNIW were investigated by the process of crystal transition from γ-HNIW to ε-HNIW in the ethyl acetate/cyclohexane system. It has been found by scanning electron microscope (SEM) that the crystal shape of ε-HNIW changes and the crystal surface is smoother with less surface defects. Compared with the crystals obtained without crystal modifier, the area of {110} planes of the crystal obtained with A₁, and the area of {011} planes of the crystal obtained with A₂ are increased. It is proved that A₁ could inhibit the growth of {110} planes and A₂ could inhibit the growth of {011} planes. The interaction between crystal modifiers and ε-HNIW crystal surface is studied by molecular dynamic simulation, which is consistent with the experimental results.