In this work, low-temperature and flexible self-powered active acetylene (C2H2) gas sensing has been realized from the piezo-plasmonic properties of Ag@ZnO nanowire (NW) arrays through visible light modulation. With the assistance of 3.48–21.47mWcm−2 visible light illumination, the piezoelectric output of the Ag@ZnO NW arrays acting as a response signal shows significant improvement over the traditional resistive-type C2H2 sensor at room temperature. Photoexcited plasmonic Ag nanoparticles (NPs) favorably modifies the intrinsic properties and increases the carrier density in the sensing surface, resulting in a strong piezoelectric screening effect. Under 12.72mWcm−2 visible light intensity (under 1.3Hz and 6N compressive forces), the sensor shows a sensitivity up to 51.7% at 1000ppm acetylene at room temperature, whereas at 90°C the sensor shows a maximum response up to 83.86%. Under the same condition, an average response time of 87s is observed (upto 1000ppm gas concentration) as well as a broad detection range of 25–1000ppm and excellent selectivity. The current results demonstrate a feasible approach for developing light modulated, low-temperature self-powered active gas sensors and their potential in smart wearable, handheld, and portable applications.