To investigate effects of potato-based emulsion (PE) on the quality of surimi gels, corn oil (CO) or PE was mixed with surimi at different additive levels (0%-14%), and the effects of PE as a fat replacer on the quality and mechanism of surimi gels were investigated by texture, moisture, color, intermolecular interactions, rheological properties, and microstructure of the surimi gels. At the same oil addition level, PE could avoid the degrading effect of oil droplets on the textural properties and water-holding capacity of surimi gels compared with CO, so that the samples added with PE exhibited higher elastic modulus and viscosity; in addition, the results of transverse relaxation time showed that PE inhibited the transition from immobile to free water, so that more immobile water was bound, which might enhance the diffuse reflection of light, thus resulting in the higher whiteness of the PE-added samples. The results of microstructure and intermolecular force measurements showed that the oil droplets in PE samples were more uniformly distributed, the hydrogen bonding, hydrophobic interactions and disulfide cross-linking were stronger, and the gel network was denser due to the filling effect of starch granules; the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the neutralization of oil droplets in the PE group intervened less in the cross-linking of surimi proteins. These results indicate that PE can be used as a fat substitute to improve the quality of surimi gels, and this study provides a theoretical basis for the development of starch-based fat substitutes and their application in surimi gelatine products