BSA and chitosan were used to prepare nanoparticles of polyphenols from the pine cones of Pinus koraiensis (PKP-NPs). The physicochemical properties including the average particle size, zeta potential, crystal characteristics and morphology of PKP-NPs were measured. PKP-NPs were semi-crystalline, and possessed spherical and almost uniformly sized morphological features. The rheological particle size of PKP-NPs was 187.9 ± 16.32 nm, and the zeta potential was −7.34 ± 0.24 mV. In addition, PKP-NPs showed excellent storage stability at room temperature. Through establishment of a simulated gastrointestinal digestion model, the release behavior and phenolic composition of PKP-NPs were respectively investigated. The results showed that nano-encapsulation could significantly elevate the sustained-release characteristics of PKP. After simulated digestion, the phenolic composition in digestive juice was totally different from that of non-encapsulated PKP, but partially consistent with that of non-digested PKP. The present research provided a theoretical basis for PKP-NPs as a novel nutrient to be used in the functional food field.