The rapid and multiplexed detection of waterborne viruses is crucial for infection prevention. However, current methods are limited by low-quality probes, instrument dependency, and time-consuming procedures. In this study, we developed a high-performance, nanobody pair-based, multichannel homogeneous platform for the simultaneous and rapid detection of three viruses─SARS-CoV-2, norovirus, and influenza A virus─in aquatic environments. To identify robust and sensitive multiepitope nanobody pairs for these viruses, we utilized pressure-assisted screening and docking techniques. For multichannel detection, we synthesized three distinct SiO2@TQD types with unique excitation wavelengths, each acting as an independent signal label. By integrating these multichannel antibody arrays and signal labels into a unified platform, we developed a homogeneous sensor capable of detecting all three viruses within 30 min. The system demonstrated detection limits of as low as 1.56 pg/mL for the SARS-CoV-2 antigen, 0.1 pg/mL for the norovirus antigen, and 0.39 pg/mL for the influenza A virus antigen, surpassing conventional antigen detection kits with a sensitivity enhancement of 160.26-6.25 × 104-fold. Notable advantages include exceptional specificity, accuracy, and stability. This work not only provides a transformative solution for monitoring waterborne pathogens but also establishes a versatile framework for developing multichannel detection platforms for other infectious agents.