This study investigates flexible quasi-solid-state SnO2/CNT nanocomposite supercapacitors fabricated using a dc-pulse nitrogen atmospheric-pressure plasma jet (APPJ). The optimal APPJ processing time is merely 15s. Cyclic voltammetry (potential scan rate=2mV/s) shows an areal capacitance of 3.86mF/cm2 when flat and 4.42mF/cm2 under bending (bending radius R =0.55cm), indicating good functionality under flexing. The capacitance retention rate is 98.3% as evaluated after a 1000-cycle cyclic voltammetry test under bending (R =0.55cm), suggesting good operational stability.