The excessive reactive oxygen species (ROS) accumulation and overactivated osteoclastogenesis in subchondral bone has proved to be a major cause of osteoarthritis (OA). Scavenging of ROS microenvironment to inhibit the osteoclastogenesis is highly valued in the therapeutic process of osteoarthritis. Despite the excellent ability of polyphenolic colloidal to scavenge reactive oxygen species and its affinity for macrophages, the preparation of polyphenolic colloidal nanoparticles is limited by the complex intermolecular forces between phenol molecules and the lack of understanding of polymerization/sol-gel chemistry. Herein, our work introduces a novel poly-tannin-phenylboronic colloidal nanoparticle (PTA) exclusively linked by ROS-responsive bondings. Nanocolloidal PTA has a uniform particle size, is easy and scalable to synthesize, has excellent scavenging of ROS, and can be slowly degraded. For in vitro experiments, we demonstrated that, PTA could eliminate ROS within RAW264.7 cells and impede osteoclastogenesis and bone resorption. RNA sequencing results of PTA-treated RAW264.7 cells further reveal the promotion of antioxidant activity and inhibition of osteoclastogenesis. For in vivo experiments, PTA could eliminate the ROS environment and reduce the number of osteoclasts in the subchondral bone, thereby alleviating the damage of subchondral bone and symptoms of osteoarthritis. Our research, by delving into the formation of polyphenol colloidal nanoparticles and validating their role in ROS scavenging to inhibit osteoclastogenesis in subchondral bone, may open new avenues for OA treatment in the future.