Consumers increasingly desire healthier low-fat snack options. In this study, potato starch served as the substrate, and varying quantities of Lycium barbarum L. polysaccharide (0, 1, 3, and 5 g/100 g) were added to formula potato chips (FPC). The effect of LBPs on the sensory qualities, oil content, microstructure, and starch properties of FPC-LBPs was examined. The results showed that LBPs resulted in enhanced acceptability, reduced oil content, increased RS content, lower straight-chain starch leaching, and a gradual increase in the composite index (CI) of polysaccharides and starch in FPC-LBPs. The FPC-1LBPs exhibited the highest acceptability compared with the control samples. As the quantity of LBPs increased, the pores and cracks in the FPC-LBPs gradually decreased, and a polysaccharide wrapping layer formed on the surface of starch, which was the primary cause of the decrease in the oil content. With an increase in LBPs addition, the long-range and short-range ordered structure of starch progressively increased, and the hydrogen bonding interaction between LBPs and starch gradually strengthened, resulting in thinner FPC-LBPs. The enthalpy change of starch gradually decreased owing to LBPs, which delayed the pasting of starch and increased the RS content.