Quartz-enhanced photoacoustic spectroscopy (QEPAS) technology invented lately uses a commercially available mm sized piezoelectric quartz tuning fork (QTF) as an acoustic wave transducer. A high Q-factor and a ~30 kHz resonance frequency of the QTF improve QEPAS selectivity and immunity to environmental acoustic noise. QEPAS sensor has the advantages of high sensitivity, selectivity and compactness. Acetylene (C2H2), a toxic and harmful gas, has great significance in high sensitive detection in many fields such as the detection of fault gases in transformers and environmental monitoring. In this paper, QEPAS technology was employed to detect C2H2. A continuous-wave distributed feedback (DFB) single mode diode laser emitting at 1.53 μm was used as the exciting source. In order to reduce the sensor background noise and simplify the data process, a wavelength modulation spectroscopy and a 2nd harmonic detection technique were employed. To increase the QEPAS signal amplitude, unlikely the usually used quartz tuning fork (QTF) with resonance frequency of 32.768 kHz, a novel QTF with 30.72 kHz was adopted as the acoustic wave tranducer. The position between laser beam and QTF and the laser wavelength modulation depth were optimized. In the meanwhile, micro-resonator was added into the QEPAS sensor system, and the length and inner diameter of the mR tubes were selected to be 4 mm and 0.5 mm, respectively. Finally, a 2.7 ppm minimum detection limit was obtained, and the corresponding normalized noise equivalent absorption (NNEA) coefficient was 1.3×10-8 cm-1·W·Hz-1/2.