High-internal-phase Pickering emulsions (HIPPEs) have been widely applied in the food and daily chemical industries. Nevertheless, conventional protein-polyphenol composite emulsions suffer from insufficient stability and uneven droplet distribution, which restrict their practical utilization. In contrast, protein-polysaccharide composite emulsions fail to balance functional properties such as antioxidant capacity.. To construct a stable HIPPEs system, this study formulated emulsions based on pea protein-tea polyphenol (PP-TP) complexes, with polyquaternium-10 cellulose (PQ-10) addition ranging from 0% to 2.5% as the variable. Multiple characterization techniques including, including Zeta potential measurement, particle size distribution detection, rheological property analysis, centrifugal and storage stability tests, optical microscopy observation, as well as DPPH and ABTS radical scavenging activity assays were adopted to systematically investigate the effects of PQ-10 on emulsion performance properties. The experimental results demonstrated that PQ-10 reversed the zeta potential of emulsions from negative to positive, with the maximum absolute value of 29.03 mV observed at a PQ-10 addition level of 2.0%. PQ-10 at concentrations of 2.0%–2.5% markedly improved emulsion stability, the droplet size decreased from 72.77 μm to 31.62 μm and presented a uniform distribution. At 2.5% PQ-10, the storage modulus (G?=322.021 Pa) and loss modulus (G??=98.811 Pa) of the emulsions reached their maximum values, demonstrating solid-like elastic behavior.. The 0% PQ-10 group showed the maximum DPPH radical scavenging efficiency, and the minimum radical scavenging performance was observed in the 2.0% PQ-10 group. This study identified 2.0%–2.5% PQ-10 as the optimal concentration range to enhance the stability and functional properties of PP-TP composite HIPPEs, which provides theoretical support for the preparation and application of functional HIPPEs.