The intimate association between telomerase activity and cancer has driven the exploration of diverse methodologies for its precise detection. However, detecting telomerase activity at the single-cell level remains a significant challenge. Herein, we present a MOF-DNA barcode-amplified CRISPR-Cas12a strategy integrated with a single-cell microfluidic chip for ultrasensitive detection of telomerase activity. DNA-functionalized UiO-66 nanoparticles act as signal transducers, effectively converting telomerase activity into DNA activation strands, which subsequently trigger the trans-cleavage activity of CRISPR-Cas12a. This amplification-based assay could be integrated with a microfluidic chip to enable highly sensitive detection of telomerase activity at the single-cell level, offering promising advancements in early cancer diagnosis.