Tunable Diode Laser Absorption Spectroscopy (TDLAS) is a prominent analytical technique for developing gas sensing systems. The near infrared absorption spectroscopy of acetylene (C₂H₂) at 6 523.879 cm^-1 was simulated and tested based on TDLAS technology. First of all, acetylene absorption spectroscopy under different pressures is simulated based on LabVIEW software and compared with the standard absorption spectroscopy in HITRAN2020 database. The results show that the absorption spectral line simulated based on LabVIEW is in good agreement with the standard spectrum, which is very suitable for the on-line gas detection system, and has the advantages of convenient operation and strong operability. Secondly, a set of acetylene absorption spectroscopy detection system was successfully established. The relative errors of acetylene absorption line strength and self-broadening coefficient with database parameters are 2.5% and 1.201%, respectively, by measuring and calculating the absorption line of acetylene within 25 mbar gas pressure. Finally, a real-time online detection program based on LabVIEW is established, which can realize accurate real-time and fast inversion of C₂H₂ concentration.