The luminescence properties of covalent organic frameworks (COFs) have attracted significant attention for biomedical applications. However, conventional fluorescent COFs often suffer from weak fluorescence due to aggregation-caused quenching (ACQ), limiting their utility. Given the critical need for highly efficient and sensitive biosensing tools, herein, we propose an aggregation-induced emission (AIE) COF, named COF-Bpy, with the quantum yield up to 25%. Benefiting from the active nitrogen sites within the bipyridine unit, COF-Bpy demonstrates remarkable pH monitoring capabilities across a wide pH range and displays strong coordination affinity towards Cu