Early detection of pancreatic cancer is vital for patient survival. However, current diagnostic approaches remain constrained by insufficient precision and specificity inherent to single-biomarker detection strategies. Herein, we develop a nanochannel biosensing platform implementing cooperative dual-signal detection of pancreatic-specific biomarkers CA19-9 and miRNA-196a. Using liquid-liquid interface self-assembly, we constructed anodic aluminum oxide (AAO)-Au hybrid nanochannels integrated with a surface-modified double-key DNA nanolock (DDN). The conformational switch of DDN logic gating triggered by miRNA-196a exposes the CA19-9-aptamer, enabling specific target recognition and consequent ion current signal attenuation. Simultaneously, released miRNA-196a is quantified by catalytic hairpin assembly and hybridization chain reaction-mediated cascade amplification. Experiments show that the present DDN-based logic nanofluidic platform could achieve an ultralow detection limit of 0.000027 U·mL