In this paper, a novel calibration-free sensing technology for absolute gas concentration and temperature based on light-induced thermoelastic spectroscopy (LITES) was demonstrated for the first time. By utilizing the quartz thermoelastic effect as the sensing mechanism, combined with full range light intensity modulation to acquire the complete target gas absorption spectrum, from which absolute gas concentration and temperature values are directly extracted, eliminating the need for calibration. This method effectively eliminates the calibration process previously essential in conventional LITES technology and can obtain the absolute gas concentration as well as the temperature directly. The experimental results also verified this technology can accurately detect the target even when the laser power, QTF characteristics, and the optical path of the system change, providing an effective technical proposal for the long-term, stable, and accurate measurement of the analyte. Furthermore, it also offers the advantage of small size and wavelength independence, which makes it well-suited for miniaturization and extending sensing to other wavebands, such as the mid-infrared and far infrared